Polar monomer containing copolymers derived from olefins useful as lubricant and fuel oil additives, processes for preparation of such copolymers and additives and use thereof

ABSTRACT

Polar monomer-containing copolymers derived from at least one α, β unsaturated carbonyl compound, such as alkyl acrylates and one or more olefins, such olefins including ethylene and C 3 -C 20  α-olefins such as propylene and 1-butene, which copolymers have (a) an average ethylene sequence length, ESL, of from about 1.0 to less than about 3.0; (b) an average of at least 5 branches per 100 carbon atoms of the copolymer chains comprising the copolymer; (c) at least about 50% of said branches being methyl and/or ethyl branches; (d) substantially all of said incorporated polar monomer is present at the terminal position of said branches; (e) at least about 30% of said copolymer chains terminated with a vinyl or vinylene group; (f) a number average molecular weight, Mn, of from about 300 to about 15,000 when the copolymer is intended for dipersant or wax crystal modifier uses and up to about 500,000 where intended for viscosity modifier uses; and (g) substantial solubility in hydrocarbon and/or synthetic base oil. The copolymers are produced using late-transition-metal catalyst systems and, as an olefin monomer source other than ethylene preferably inexpensive, highly dilute refinery or steam cracker feed streams that have undergone only limited clean-up steps. Fuel and lubricating oil additives, are produced. Where functionalization and derivatization of these copolymers is required for such additives it is facilitated by the olefinic structures available in the copolymer chains.

This is a divisional of application Ser. No. 08/897,959, filed Jul. 21,1997, now U.S. Pat. No. 6,066,603.

FIELD OF THE INVENTION

The invention relates to copolymers derived from polar monomers such asalkyl acrylates and olefinic monomers such as ethylene, C₃-C₂₀α-olefins, and mixtures thereof, which possess a specific combination ofchemical and physical properties rendering the copolymers particularlysuitable as “polymer (or copolymer) backbones” for the preparation offuel and lubricating oil additives, particularly dispersants, viscositymodifiers and flow improvers. The invention also relates to improvedoil-soluble dispersant additives prepared from the copolymers and usefulin fuel and lubricating oil compositions, and to concentrates containingthe oil-soluble dispersant additives. Furthermore, the invention relatesto a continuous process for the copolymerization of at least one alkylacrylate and at least one of ethylene, α-olefins and mixtures ofethylene and α-olefins using a late-transition-metal catalyst system,and where an α-olefin monomer is used, using it in the form of a highlydiluted α-olefin feed, preferably obtained from a refinery or steamcracker feedstream.

BACKGROUND OF THE INVENTION

Hydrocarbon oil and fuel oil compositions typically include additives toenhance performance. For example, such oils typically comprise a mixtureof at least one hydrocarbon base oil and one or more additives, e.g.,dispersant, viscosity modifier, wax crystal modifier (e.g., pour pointdepressant), detergent, antioxidant, etc. additives, where each additiveis employed for the purpose of improving the performance and propertiesof the base oil in its intended application; e.g., as a lubricating oil,heating oil, diesel oil, middle distillate fuel oil, power transmissionfluid and so forth.

Dispersants are typically polymeric materials with an oleophiliccharacteristic providing oil solubility and a polar characteristicproviding dispersancy. The number average molecular weight of a polymer“backbone” used as a vehicle for synthesizing a dispersant is generally10,000 or less.

Viscosity modifiers also are typically polymeric materials that can beused neat or with suitable functionalization and/or derivatization beused as multifunctional viscosity modifiers. When used as viscositymodifiers the polymer or copolymer backbone generally has a numberaverage molecular weight of greater than about 15,000.

Dispersants used in lubricating oils typically are hydrocarbon polymersor copolymers modified to contain nitrogen- and ester-based groups.Polyisobutylene is commonly used in the preparation of dispersants,although other hydrocarbon polymers, such as ethylene-α-olefincopolymers, can be employed as well. It is the primary function of adispersants to maintain in suspension in the oil those insolublematerials formed by oxidation, etc. during use, thereby preventingsludge flocculation and precipitation. The amount of dispersant employedis dictated by the effectiveness of the particular material in achievingits dispersant function. Dispersants can have additional functions, suchas viscosity modifying properties and antioxidancy, depending on theirchemical and structural characteristics.

Nitrogen- and ester-based dispersants can be prepared by firstfunctionalizing a long-chain hydrocarbon polymer, e.g., polyisobutylene,and ethylene α-olefin (EAO) copolymers with maleic anhydride to form thecorresponding polymer substituted with succinic anhydride groups, andthen derivatizing the succinic anhydride-substituted polymer with anamine or an alcohol or the like. Polyisobutylene generally containsresidual unsaturation in amounts of about one ethylenic double bond perpolymer chain, positioned along the chain, whereas the more recentlydeveloped EAO copolymers (based on metallocene catalyst systems) containa substantial amount of terminal vinylidene unsaturation (see, e.g., WO94/19436, published Sep. 1, 1994, incorporated herein for the purposesof U.S. patent prosecution.) The ethylenic double bonds serve as sitesfor functionalization by, for example, the thermal “ene” reaction (i.e.,by direct reaction with maleic anhydride or one or more otherdicarboxylic acid moieties).

Polyisobutylene (PIB) polymers employed in conventional dispersants aresometimes limited by viscosity effects associated with the polymer aswell as limited reactivity. EAO copolymers offer improvements, sincethese products are primarily terminated with vinylidene typeunsaturation, but there are additional efficiencies which can berealized with further improvements in reactivity for functionalizationand derivatization; also such copolymers require the use of multiplemonomer feed steams to produce a copolymer.

The use of highly diluted, purified refinery monomer feedstreams forethylene and α-olefin polymerization using a metallocene catalyst systemto produce an ethylene α-olefin copolymer has been disclosed in U.S.Ser. No. 992,690 (filed Dec. 17, 1992), incorporated herein for thepurposes of U.S. patent prosecution. As a consequence of using aZiegler-Natta catalyst generally, or a metallocene based catalyst systemspecifically, there are necessary concerns about the purity of thefeedstreams since such catalyst systems are particularly sensitive tomoisture as well as nitrogen, sulfur and oxygen compounds which candeactivate the catalyst (see, e.g., WO93/24539, page 13, published Dec.9, 1993).

Johnson, L. K. et al., in J. Am Chem Soc., 1995, 117, 6414, describe theuse of Ni and Pd complexes using various activators (including MAO andalkyl aluminum chloride) for the solution homopolymerization ofethylene, propylene, and 1-hexene. Polymers varying in molecular weight,branch length and crystallinity are disclosed.

Johnson, L. K. et al., in J. Am Chem Soc., 1996, 118, 267, describe thesolution copolymerization of ethylene with acrylate comonomers,including methyl acrylate, tert-butyl acrylate, perfluorinated octylacrylate, and methyl vinyl ketone and propylene with methyl acrylate andperfluorinated octyl acrylate, using a Pd catalyst. The copolymers aredisclosed as random, amorphous, and branched (it is stated the ethylenecopolymers have approximately 100 branches/1000 C atoms) with functionalgroups located predominantly at branch ends.

Brookhart, M. S. et al., in published patent application EP 0 454 231 A2(1991) describe a catalyst for the polymerization of ethylene,α-olefins, diolefins, functionalized olefins, and alkynes. The generaldescription of the catalyst broadly includes Group VIIIb metals (Groups8, 9, 10); cobalt and nickel are exemplified in solution polymerizationsto produce oligomers and polymers of limited molecular weight.

Brookhart, M. et al. in J. Am. Chem. Soc., 1994, 116, 3641 and 1992,114, 5894 describe the use of Pd(II) catalysts to produce alternatingolefin/CO copolymers. (Subsequently, it is noted in J. Am Chem Soc.,1995, 117, 6414 that the complexes used in the 1992 reference onlydimerize ethylene.)

Keim, W. et al. in Angew. Chem., Int. Ed. Engl., 1981, 20, 116 describethe use of an aminobis(imino)phosphorane complex of Ni to polymerizeethylene under pressure in a toluene solution. The polymer is said tocontain short chain branches.

Möhring, V. M. et al. in Angew. Chem., Int. Ed. Engl., 1985, 24, 1001describe the use of the catalyst system aminobis(imino)phosphoranecomplex of Ni to polymerize C₃ to C₂₀ linear α-olefins and singlybranched α-olefins. Olefins containing quaternary carbons, vinylene, orvinylidene groups did polymerize, but copolymers of α-olefins could beobtained. Polymerization of linear α-olefins produced polymerscontaining methyl branches evenly spaced corresponding to the length ofthe olefin chain. (A “chain running” mechanism proposed as anexplanation for the branched polymer structure is also described by L.K. Johnson in J. Am Chem Soc., 1995, 117, 6414, above.)

Peuckert, M. et al. in Organometallics, 1983, 2, 594 describe a Nicatalyst for the oligomerization of ethylene in toluene. The catalystsare said to contain the chelating phosphino-acetate ligand used in SHOPcatalysts. The C₄ to C₂₄ oligomers are >99% linear and >93% α-olefin. Anethylene/hexene co-oligomerization produced product with no detectablebranches.

A component described as useful in lubricating oil flow improversdescribed in U.S. Pat. No. 4,839,074 includes polymers and interpolymersof side chain unsaturated monoesters which are unsaturated esters,generally acrylate or 2-alkylacrylate monoesters represented by adefined formula.

It has been found in the present invention, that further improvementscan be achieved in the performance of fuel and lubricant additives,particularly including ashless dispersants and wax crystal modifiers,based on the use of copolymers derived from polar and olefinic monomers;also, significant improvements in the economics of producing and usingsuch additives can be achieved by selective use of late-transition-metalcatalysts and polymerization processes which use highly dilute refineryor steam cracker olefin feedstreams to produce a copolymer having aunique combination of properties for subsequent functionalization andderivatization.

SUMMARY OF THE INVENTION

Hydrocarbon copolymers derived from polar and olefinic monomers whichare suitable for use as a fuel or lubricant additives, e.g., polarmonomers including alkyl acrylates and olefinic monomers includingethylene and α-olefins such as propylene, 1-butene, etc. (suchcopolymers referred to, for convenience, as “polar-olefin hydrocarbon”copolymers or POH copolymers), characterized by a complex set ofproperties: (a) an average ethylene sequence length, ESL, of from about1.0 to less than about 3.0; (b) an average of at least 5 branches per100 carbon atoms of the copolymer chains comprising said copolymer; (c)at least about 50% of such branches being methyl and/or ethyl branches;(d) at least about 30% of the copolymer chains terminated with a vinylor vinylene group; (e) a number average molecular weight, Mn of formabout 300 to about 10,000 for dispersant uses and from about 15,000 toabout 500,000 for viscosity modifier uses; and (f) substantialsolubility of the copolymer in hydrocarbon and/or synthetic base oil.

This combination of properties yields POH copolymers of the inventionespecially suitable for use as polymer/copolymer backbones in thepreparation of lubricating and fuel oil additives, particularlydispersant additives, as well as for use as wax crystal modifiers andviscosity modifiers. When used as a dispersant backbone, the limitedrange of number average molecular weight characterizing the POHcopolymers of the present invention ensures that dispersants producedtherefrom are substantially soluble in lubricating base oils, and,simultaneously, avoids or reduces handling problems due to highviscosity levels and wax crystal interactions. Furthermore, the definedcopolymer properties also result in products which have the desiredlevel of wax interaction for their use as wax crystal modifiers and thesolution viscosity/temperature properties for use as viscositymodifiers. Because of the relatively high level of terminal vinyl andvinylene unsaturation in the inventive POH copolymers, the dispersantadditives produced therefrom have high active ingredient concentrations,thereby providing enhanced lubricating oil dispersancy, includingenhanced sludge and varnish control properties.

The copolymers of the present invention are preferably produced using aprocess which employs as the monomer(s) highly dilute refinery or steamcracker feedstream(s) based on C₃, C₄ or C₅ sources with or withoutadded ethylene. The process is particularly advantageous in that themonomer feedstream need not be totally free of materials which wouldotherwise be poisons for Ziegler-Natta or metallocene based catalystsystems.

Furthermore, the copolymers of the present invention and the dispersantadditives produced therefrom, will possess enhanced pour pointperformance in lubricating oil compositions to which they are added,particularly in compositions which also contain conventional lubricatingoil flow improvers (LOFI's). This beneficial pour point behavior of thedispersants is believed to be attributable in part to the uniquecopolymer chain structure achievable with the late-transition-metalcatalyst system.

A further aspect of this invention relates to the POH copolymerfunctionalized with reactive groups, such as by substitution with mono-or dicarboxylic acid materials (i.e., acid, anhydride or acid ester)produced by reacting (e.g., by the “ene” reaction) the POH copolymers ofthe invention with mono-unsaturated carboxylic reactants. Themonocarboxylic acid and the dicarboxylic acid or anhydride substitutedPHO copolymers are useful per se as additives to lubricating oils, and,in another aspect of this invention, can also be reacted withnucleophilic reagents, such as amines, alcohols, amino alcohols andmetal compounds, to form derivative products which are also useful aslubricating oil additives, e.g., as dispersants.

In still another aspect of this invention, lubricating oil additives areproduced by functionalizing the POH copolymers of the invention usingreactants other than the mono-unsaturated carboxylic reactants describedabove. Accordingly, the copolymer can be functionalized by reaction witha hydroxy aromatic compound in the presence of a catalytically effectiveamount of at least one acidic alkylation catalyst. Subsequently, thealkylated hydroxyaromatic compound can be reacted by Mannich Basecondensation with an aldehyde and an amine reagent to provide aderivatized copolymer.

Lubricating oil additives within the scope of this invention are alsoproduced by oxidation of the POH copolymer of the invention, such asoxidation with a gas containing oxygen and/or ozone. The copolymer canalso be functionalized by hydroformylation and by epoxidation. The POHcopolymers can also be functionalized by contacting the copolymers underKoch reaction conditions with carbon monoxide in the presence of anacidic catalyst and a nucleophilic trapping agent such as water or ahydroxy-containing compound or a thiol-containing compound to formcarboxyl groups on the copolymer. Functionalization can also beaccomplished using “Reppe” reaction chemistry (as described in acopending application, U.S. Ser. No. 663,465, filed Jun. 17, 1996, andincorporated herein by reference for the purposes of U.S. prosecution).Furthermore, the aforesaid functionalized copolymers formed byoxidation, hydroformylation, epoxidation, and Koch reaction can bederivatized by reaction with at least one derivatizing compound to formderivatized copolymers.

DETAILED DESCRIPTION OF THE INVENTION

When used in the disclosure and claims, the terms “polymer” and“copolymer” are used interchangeably unless the terms are otherwisespecifically distinguished. The present invention relates to copolymersderived from polar monomers such as alkyl acrylates and olefinicmonomers such as ethylene, propylene and 1-butene characterized by acertain combination of chemical and physical properties which makes thecopolymers especially suitable for use as the backbone of dispersantadditives. More particularly, the polar-olefinic hydrocarbon (POH)copolymers of the invention possess a relatively high degree of terminalvinyl and/or vinylene unsaturation, a number average molecular weightwithin defined ranges, controlled ethylene sequence length withincopolymer chains, and the ability to form mineral and/or synthetic oilsolutions. Each of these properties contributes in one or more respectsto the utility of the copolymer as a dispersant backbone.

Preparation of the Polar-Olefinic Hydrocarbon Copolymer

Polar-olefinic hydrocarbon (“PHO”) copolymers of the present inventionhaving a relatively high degree of terminal vinyl and/or vinyleneunsaturation, for example, at least about 30% of the copolymer chains,can be prepared by polymerizing at least one olefinic monomer selectedfrom the group consisting of (a) ethylene, (b) one or more α-olefins or(c) mixtures of (a) and (b) and optionally, an additional polyene, inthe presence of a late-transition-metal catalyst system described below.The POH copolymer chain structure can be controlled through theselection of the late-transition-metal catalyst system and bycontrolling the relative proportions of the ethylene and/or otherα-olefins. One preferred method for preparing the POH copolymers isdescribed in more detail below; it is based on the use of one or morehighly diluted monomer feedstreams originating in a refinery or steamcracker.

The polymerization catalyst useful for this invention can be derivedfrom the late-transition-metal compounds of formula:

LMX_(r)

wherein M is a Group 9, 10, or 11 metal, preferably a d⁶, d⁸ or d¹⁰metal, most preferably d⁸ (wherein “Group” refers to the identifiedgroup of the Periodic Table of Elements, comprehensively presented in“Advanced Inorganic Chemistry,” F. A. Cotton, G. Wilkinson, FifthEdition, 1988, John Wiley & Sons);

L is a bidentate ligand that stabilizes a square planar geometry andcharge balances the oxidation state of MX_(r);

each X is, independently, a hydride radical, a hydrocarbyl radical, asubstituted hydrocarbyl radical, a halocarbyl radical, a substitutedhalocarbyl radical, and hydrocarbyl- and halocarbyl-substitutedorganometalloid radicals; or two X's are joined and bound to the metalatom to form a metallacycle ring containing from about 3 to about 20carbon atoms; or one or more X can be a neutral hydrocarbyl containingdonor ligand, e.g., an olefin, diolefin, aryne ligand; and r=0, 1, 2, or3. When Lewis-acid activators, such as methylalumoxane, aluminum alkylsor alkylaluminum halides, which are capable of donating an X ligand asdescribed above to the transition metal component, are used, one or moreX may additionally be independently selected from the group consistingof a halogen, alkoxide, aryloxide, amide, phosphide or other univalentanionic ligand or two such X's joined to form an anionic chelatingligand; or one or more neutral non-hydrocarbyl atom containing donorligand, e.g., phosphine, amine, nitrile or CO ligand.

In a preferred embodiment of the invention, the bidentate ligand, L, isdefined by the following formula:

wherein A is a bridging containing a Group 13-15 element;

each E is independently a Group 15 or 16 element bonded to M;

each R is independently a C₁-C₃₀ containing radical group which is ahydrocarbyl, substituted-hydrocarbyl, halocarbyl,substituted-halocarbyl, hydrocarbyl-substituted organometalloid,halocarbyl-substituted organometalloid;

m and n are independently 1 or 2, depending on the valency of E; and

p is the charge on the bidentate ligand such that the valency of MX_(r)is satisfied.

In the most preferred embodiment of the invention, the bridging group,A, is defined by the following formula:

wherein G is Group 14 element especially C, Si, and Ge;

Q is a Group 13 element especially B, and Al; and

R′ are independently hydride radicals, C₁-C₃₀ hydrocarbyl radicals,substituted hydrocarbyl radicals, halocarbyl radicals, substitutedhalocarbyl radicals, and hydrocarbyl- and halocarbyl-, substitutedorganometalloid radicals, and optionally two or more adjacent R′ mayform one or more C₄ to C₄₀ ring to give a saturated or unsaturatedcyclic or polycyclic ring.

Also in the most preferred embodiment of the invention, R is a bulkyC₁-C₃₀ containing radical group which is a hydrocarbyl,substituted-hydrocarbyl, halocarbyl, substituted-halocarbyl,hydrocarbyl-substituted organometalloid, halocarbyl-substitutedorganometalloid. Bulky radical groups include phenyls, substitutedphenyls, alkyls and substituted alkyls, especially those bonded to Ethrough a tertiary carbon atom, alicyclics and polyaclicyclicscontaining hydrocarbyls, especially those bonded to E though a tertiarycarbon and the like.

In the definitions above, the term “substituted” is as defined or refersto C₁-C₃₀ containing radials which are to be essentially hydrocarbyl,but may include one or more non-hydrocarbyl atoms (such as Si, Ge, O, S,N, P, halogen, etc.) in place of one or more carbon atoms.

In the very most preferred embodiment of this invention, M is a group 10metal, E is a group 15 element, especially nitrogen, with m and n beingone and p being zero, the bridge is as drawn in A-1, and R is asubstituted phenyl group preferably substituted in at least the 2 and 6positions with R′ groups. The use of Pd is particularly preferred forcopolymerization of polar monomers such as α, β unsaturated carbonylcompounds such as alkyl acrylates and methyl vinyl ketone, as definedhereinafter.

Various forms of the catalyst system of the late-transition-metal typemay be used in the polymerization process of this invention. Severaldisclosures in the art which include such catalysts are discussed aboveand are incorporated herein by reference for the purposes of U.S.prosecution; these publications teach the structure of variouslate-transition-metal catalysts and include alumoxane as a cocatalyst.There are a variety of methods for preparing alumoxane, one of which isdescribed in U.S. Pat. No. 4,665,208, and it is also availablecommercially.

For the purposes of this patent specification, the terms “cocatalysts oractivators” are used interchangeably and are defined to be any compoundor component which can activate a bulky ligand transition metalcompound. The late-transition-metal catalyst compounds according to theinvention may be activated for polymerization catalysis in any mannersufficient to allow coordination polymerization. This can be achieved,for example, when one X ligand can be abstracted and the other X willeither allow insertion of the unsaturated monomers or will be similarlyabstractable for replacement with an X that allows insertion of theunsaturated monomer. The traditional activators of mettallocenepolymerization art are suitable activators; those typically includeLewis acids such as alumoxane compounds, and ionizing, anion pre-cursorcompounds that abstract one X so as to ionize the transition metalcenter into a cation and provide a counterbalancing, compatible,noncoordinating anion.

Alkylalumoxanes and modified alkylalumoxanes are suitable as catalystactivators. The alumoxane component useful as catalyst activatortypically is an oligomeric aluminum compound represented by the generalformula (R″—Al—O)_(n), which is a cyclic compound, orR″(R″—Al—O)_(n)AlR″₂, which is a linear compound. In the generalalumoxane formula R″ is independently a C₁ to C₁₀ alkyl radical, forexample, methyl, ethyl, propyl, butyl or pentyl and “n” is an integerfrom 1 to about 50. R″ may also be, independently, halogen, includingfluorine, chlorine and iodine, and other non-hydrocarbyl monovalentligands such as amide, alkoxide and the like, provided that not morethan 25% of R″ is methyl and “n” is at least 4. Alumoxanes can beprepared by various procedures known in the art. For example, analuminum alkyl may be treated with water dissolved in an inert organicsolvent, or it may be contacted with a hydrated salt, such as hydratedcopper sulfate suspended in an inert organic solvent, to yield analumoxane. Generally, however prepared, the reaction of an aluminumalkyl with a limited amount of water yields a mixture of the linear andcyclic species of the alumoxane. Methylalumoxane and modifiedmethylalumoxanes are preferred. For further descriptions see, U.S. Pat.Nos. 4,665,208, 4,952,540, 5,041,584, 5,091,352, 5,206,199, 5,204,419,4,874,734, 4,924,018, 4,908,463, 4,968,827, 5,329,032, 5,248,801,5,235,081, 5,157,137, 5,103,031 and EP 0561 476 Al, EP 0 279 586 131, EP0 516 476 A, EP 0594 218 Al and WO 94/10180, each being incorporated byreference for purposes of U.S. patent practice.

When the activator is an alumoxane, the preferred transition metalcompound to activator molar ratio is from 1:10000 to 10:1, morepreferably from about 1:5000 to 10:1, even more preferably from about1:1000 to 1:1.

The term “noncoordinating anion” as used for the ionizing, anionpre-cursor compounds is recognized to mean an anion which either doesnot coordinate to said transition metal cation or which is only weaklycoordinated to said cation thereby remaining sufficiently labile to bedisplaced by a neutral Lewis base. “Compatible” noncoordinating anionsare those which are not degraded to neutrality when the initially formedcomplex between the late-transition-metal catalyst compounds and theionizing, anion pre-cursor compounds decomposes. Further, the anion willnot transfer an anionic substituent or fragment to the cation so as tocause it to form a neutral four coordinate metal compound and a neutralby-product from the anion. Noncoordinating anions useful in accordancewith this invention are those which are compatible, stabilize thelate-transition-metal cation in the sense of balancing its ionic chargein a +1 state, yet retain sufficient lability to permit displacement byan olefinically unsaturated monomer during polymerization. Additionally,the anions useful in this invention will be large or bulky in the senseof sufficient molecular size to partially inhibit or help to preventneutralization of the late-transition-metal cation by Lewis bases otherthan the polymerizable monomers that may be present in thepolymerization process.

Descriptions of ionic catalysts, those comprising a transition metalcation (based on metallocenes) and a non-coordinating anion, suitablefor coordination polymerization appear in U.S. Pat. Nos. 5,064,802,5,132,380, 5,198,401, 5,278,119, 5,321,106, 5,347,024, 5,408,017, WO92/00333 and WO 93/14132. These references teach a preferred method ofpreparation wherein metallocenes are protonated by an anion precursorsuch that an alkyl/hydride group is abstracted from a transition metalto make it both cationic and charge-balanced by the non-coordinatinganion. These teachings may be useful to those skilled in the art for thelate-transition-metal catalysts of the present invention.

The use of ionizing ionic compounds not containing an active proton butcapable of producing both the active metal cation and an noncoordinatinganion is also known. See, EP-A-0 426 637, EP-A-0 573 403 and U.S. Pat.No. 5,387,568. Reactive cations other than the Broönsted acids includeferrocenium, silver, tropylium, triphenylcarbenium and triethylsilylium,or alkali metal or alkaline earth metal cations such as sodium,magnesium or lithium cations. A further class of noncoordinating anionprecursors suitable in accordance with this invention are hydrated saltscomprising a alkali metal or alkaline earth metal cations and anon-coordinating anion as described above. The hydrated slats can beprepared by reaction of the metal cation-non-coordinating anion saltwith water, for example, by hydrolysis of the commercially available orreadily synthesized LiB(pfp)₄ which yields [Li.xH₂O][B(pfp)₄], where(pfp) is pentafluorophenyl or perfluorophenyl.

Any metal or metalloid capable of forming a coordination complex whichis resistant to degradation by water (or other Brönsted or Lewis Acids)may be used or contained in the anion. Suitable metals include, but arenot limited to, aluminum, gold, platinum and the like. Suitablemetalloids include, but are not limited to, boron, phosphorus, siliconand the like. The description of non-coordinating anions and precursorsthereto of the documents of the foregoing paragraphs are incorporated byreference for purposes of U.S. patent practice.

An additional method of making the ionic catalysts uses ionizing anionprecursors which are initially neutral Lewis acids but form the cationand anion upon ionizing reaction with the late-transition-metalcompounds, for example tris(pentafluorophenyl)boron acts to abstract ahydrocarbyl, hydride or silyl ligand to yield a late-transition-metalcation and stabilizing non-coordinating anion; see EP-A-0 427 697 andEP-A-0 520 732 which are directed to metallocene catalyst systems. Ioniccatalysts for coordination polymerization can also be prepared byoxidation of the metal centers of transition metal compounds by anionicprecursors containing metallic oxidizing groups along with the aniongroups, see EP-A-0 495 375. The description of non-coordinating anionsand precursors thereto of these documents are similarly incorporated byreference for purposes of U.S. patent practice.

When the cation portion of an ionic non-coordinating precursor is aBrönsted acid such as protons or protonated Lewis bases (excludingwater), or a reducible Lewis acid such as ferricinium or silver cations,or alkaline metal or alkaline earth metal cations such as those ofsodium, magnesium or lithium cations, the transition metal to activatormolar ratio may be any ratio, but preferably from about 10:1 to 1:10;more preferably from about 5:1 to 1:5; even more preferably from about2:1 to 1:2; and most preferably from about 1.2:1 to 1:1.2 with the ratioof about 1:1 being the most preferred.

A further useful method of activating the late-transition-metal catalystis to employ a Ziegler cocatalyst. Such cocatalysts will typically beorganometallic compounds of a metal of Groups 1, 2, 12, or 13 of thePeriodic Table selected form the group consisting of aluminum alkyl,aluminum alkyl halide and aluminum halide. These can be represented bythe formulas:

Al (R)_(m)(R′)_(n) X_(3−m−n) wherein R′ and R are independentlyhydrocarbyl, including C₁ to C₁₀ aliphatic, alicyclic or aromatichydrocarbon radicals which may be the same or different; X is a halogensuch as chlorine, bromine or iodine; m and n are integers from 0 to 3and the sum of (m + n) ≦ 3; and Al₂R₃X₃ which are hydrocarbylaluminumsesquihalides, such as Al₂Et₃Cl₃ and Al₂(iBu)₃Cl₃; wherein Et is ethyland iBu is isobutyl.

Examples include triethyl aluminum, diethyl aluminum chloride, Al₂Et₃Cl₃and Al₂(iBu)₃cl₃. As is generally recognized in the art, these Zieglercocatalyst compounds will not effectively activate metallocene catalystcompounds. In a preferred method this activator is reacted with thelate-transition-metal catalyst prior to addition of the activatedcatalyst system to the polymerization reactor.

Further useful late-transition-metal catalysts include those which areknown as supported catalysts. Useful catalyst systems of this type aredisclosed in the U.S. patent application titled “Supported LateTransition Metal Catalyst Systems” (G. A. Vaughan et al., U.S. Ser. No.60/020,095, filed Jun. 17, 1996; incorporated herein by reference forpurposes of U.S. prosecution).

When using ionic catalysts of the late-transition-metals comprisingcations and non-coordinating anions, the total catalyst system canadditionally comprise one or more scavenging compounds. The term“scavenging compounds” is meant to include those compounds effective forremoving polar impurities form the reaction environment. Impurities canbe inadvertently introduced with any of the polymerization reactioncomponents, particularly with solvent, monomer and catalyst feed, andadversely affect catalyst activity and stability. Impurities can resultin decreased, variable or even elimination of catalytic activity,particularly when a late-transition-metal cation-noncoordinating anonpair is the catalyst system. The polar impurities, or catalyst poisonsinclude water, oxygen, metal impurities, etc. While thelate-transition-metal catalysts of the present invention can be lesssensitive to impurities than those of the prior art, e.g., metallocenecatalyst systems, reduction or elimination of poisons is a desirableobjective. Preferably steps are taken before provision of such into thereaction vessel, for example by chemical treatment or careful separationtechniques after or during the synthesis or preparation of the variouscomponents; some minor amounts of scavenging compound can still normallybe used in the polymerization process itself.

Typically the scavenging compound will be an organometallic compoundsuch as the Group 13 organometallic compounds of U.S. Pat. Nos.5,153,157, 5,241,025 and WO-A-91/09882, WO-A-94/03506, WO-A-93/14132,and that of WO 95/07941. Exemplary compounds include thiethyl aluminum,triethyl borane, triisobutyl aluminum, methylalumoxane, isobutylaluminoxane, and n-octyl aluminum. Those scavenging compounds havingbulky or C₈-C₂₀ linear hydrocarbyl substituents covalently bound to themetal or metalloid center being preferred to minimize adverseinteraction with the active catalyst. When alumoxane is used asactivator, any excess over the amount of late-transition-metal presentwill act as scavenger compounds and additional scavenging compounds maynot be necessary. The amount of scavenging agent to be used withlate-transition-metal cation-non-coordinating anion pairs is minimizedduring polymerization reactions to that amount effective to enhanceactivity.

Polymerization Process

Generally, the polymerization process is preferably conducted in acontinuous manner by simultaneously feeding a polymerizable polarmonomer feedstream, one or more refinery or steam cracker feedstreamcontaining the olefinic monomers(s), or separate streams of reactiondiluent (if employed), monomers, catalyst an cocatalyst to a reactor andwithdrawing solvent, unreacted monomer and copolymer from the reactor,allowing sufficient residence time to form copolymer of the desiredmolecular weight, and subsequently separating the copolymer from thereaction mixture. If desired, the monomers can be premixed prior tointroducing them into the reactor.

The preferred process for producing the POH copolymer is a continuousprocess using a highly diluted, refinery or steam cracker monomerfeedstream in combination with a late-transition-metal catalyst system.Several advantages result from such a process:

(1) the use of dilute monomer feeds results in a lower concentrationgradient at the point of monomer introduction into the reactor and,consequently, less time is required to achieve uniform monomer mixingand less time is available for higher molecular weight species formationat the input port;

(2) the use of dilute feeds enables the process to operate at highconversion rates without the attendant buildup of mass transferresistance attributable to copolymer formation in pure feed systems;

(3)in a preferred embodiment of the process of the present inventionemploying a boiling reactor and dilute feed, monomer in the vapor spaceand in the liquid reaction mixture are in equilibrium, particularly whenethylene is used as a comonomer. This is achievable because of the easeof attaining uniform mixing resulting in a reaction mixture havingessentially no mass transfer resistance at the liquid/vapor interface;

(4) still further improvements are possible [where two or more monomersare polymerized] by the presence of a high concentration of diluent inthe olefin feed, such that the major constituents of the diluent boil atabout the same temperature as the α-olefin(s) to be polymerized or,where applicable, copolymerized with, e.g., ethylene. Accordingly, wherecopolymerization with ethylene is involved, ethylene content in thevapor space is further diluted by the α-olefin feed constituents, amajor portion of which is diluent. Thus, evaporative cooling does notdepend on recycle of high amounts of ethylene in the vapor, ethylenebuildup in the reflux is further minimized, and mass transfer resistanceto ethylene mixing is further reduced;

(5) a boiling reactor allows the polymerization reaction to beaccomplished in a highly isothermal manner because the heat of reactionis easily removed by boiling unreacted monomer and diluents out of thereaction media at nearly constant temperatures, resulting in a narrowermolecular weight distribution POH copolymer;

(6) where a copolymer is produced, uniformity of the copolymer isgreatly enhanced without the need for manipulation of the condensedvapor to alter its compositional distribution;

(7) the combined use of dilute feed and high conversion facilitatesremoval of catalyst (deashing) residue and quenching of thecopolymer/catalyst mixture since it is easier to mix the copolymer withdeashing and quench media;

(8) use of dilute α-olefin containing feeds and high conversion allowsfor a significant improvement in the overall economics of the processbecause such dilute feeds can be readily obtained at very low cost asby-product or waste streams derived from other commercial sources, forexample, refinery or steam cracker feed streams containing C₃, C₄ or C₅olefins.

Copolymers produced in accordance with the process of the presentinvention are copolymers comprising monomer units derived from at leastone olefin such as ethylene and α-olefins. Such monomers arecharacterized by the presence within their structure of at least oneethylenically unsaturated group of the structure >C═CH₂ and are highlyreactive at low catalyst concentrations. Late-transition-metal catalyzedpolymerizations are particularly adaptable for use with ethylene andα-olefin monomers; other olefinically unsaturated monomers may be lessreactive. Therefore, various components in suitable refinery or steamcracker streams such as a Raffinate-2 stream (e.g., components such as2-butenes, and isobutylene), may have limited reactivity in the presenceof a late-transition-metal catalyst system. Such components may beconsidered diluents in the present process and need not be separatedform the polymerizable component(s) of the feedstream. Otherconstituents which may be undesirable, such as butadiene, are madenon-reactive or non-poisonous to the catalyst by pre-saturating thedouble bonds with hydrogen.

Accordingly, suitable α-olefin monomers include those represented by thestructural formula H₂C═CHR¹ wherein R¹ straight chain or branched chainalkyl radical comprising 1 to 18 carbon atoms and wherein the copolymerformed therefrom contains a high degree of terminal vinyl and vinyleneunsaturation. Preferably R¹ in the above formula is alkyl of from 1 to16 carbon atoms, more preferably alkyl of from 1 to 12 carbon atoms,particularly for use as wax crystal modifiers. Those monomers suitablefor preparing copolymers intended for use as dispersant backbones aretypically those where R¹ in the above formula is alkyl of from 1 to 8carbon atoms, preferably alkyl of from 1 to 6 carbon atoms. Therefore,useful monomers include ethylene, propylene, butene-1, pentene-1,4-methylpentene-1, hexene-1, octene-1, decene-1, dodecene-1,tridecene-1, tetradecene-1, pentadecene-1, pentadecene-1, hexadecene-1,heptadecene-1, octadecene-1, nonadecene-1 and mixtures thereof (e.g.,mixtures of ethylene and butene-1, ethylene and propylene, propylene andbutene-1, octene-1 and tetradecene-1 and the like).

After polymerization and, optionally deactivation of the catalyst (e.g.,by conventional techniques such as contacting the polymerizationreaction medium with an excess of water or an alcohol, such as methanol,propanol, isopropanol, etc., or cooling or flashing the medium toterminate the polymerization reaction), the product copolymer can berecovered by processes well known in the art. Any excess reactants maybe flashed off from the copolymer.

The polymerizable polar monomer useful in the present invention is an α,β unsaturated carbonyl compound selected from the group represented bythe formula:

wherein X is hydrogen (H), NH₂, R_(y) or OR_(y); R_(x) is H or a C₁-C₅straight or branched alkyl group and R_(y) is H or a C₁ to C₂₀ straightor branched alkyl group; for short chain unsaturated ester monomers,R_(y) is preferably a C₁-C₅ alkyl group and for long chain monomers,preferably a C₁₀ to C₁₈ alkyl group. Representative acrylate monomerssuitable for use in the present invention include methyl acrylate,methyl methacrylate, ethyl acrylate, propyl methacrylate, propylethacrylate, butyl acrylate, tert-butyl acrylate, octyl propacrylate,decyl butacrylate, dodecyl pentacryalate, hexyl methacrylate, octylethacrylate, decyl methacrylate, dodecyl methacrylate, tetradecylmethacrylate, hexadecyl methacrylate, octadedcyl methacrylate, tridecylacrylate, tetradecyl methacrylate, pentadecyl acrylate, hexadecylacrylate and octadecyl acrylate. A preferred aldehyde is acrolein(CH₂═CHCHO), a preferred ketone is methyl vinyl ketone (CH₂═CHCOCH₃) anda preferred compound wherein X is NH₂ is acrylamide (CH₂═CHCONH₂).

The minimum number of carbon atoms of the R_(y) substituent is typicallyselected to avoid insolubility of the copolymer in the fuel orlubricating oil and the maximum number of carbon atoms is selected toavoid crystallization of the copolymer out of the fuel or lubricatingoil at low temperatures.

The concentration of polar moiety in the copolymer resulting fromcopolymerization of the polar monomer described above can range fromabout 1 to about 6 per chain, preferably from about 1 to about 2 perchain where such copolymer is used to produce dispersants usingpolyamines in combination with chain-stopping agents (as describedlater) in order to avoid the formation of gel or oil insolubledispersant product. The concentration of polar moiety can preferablyrange from about 2 to about 6 per chain where the amine used to producethe dispersant is a “1-armed” amine (as described later). Generally thepolar moiety can be present in said copolymer used to producedispersants at an average concentration of from about one polar moietyfor each 5,000 Mn segment of polymer backbone, including branches, toabout one polar moiety for each 1,000 Mn segment.

The polymerization is preferably conducted employing as the reactionmedium, a highly diluted monomer feedstream obtained from a refinery orsteam cracker. In such a medium there is present a hydrocarbon inert tothe polymerization such as butane, isobutane, pentane, isopentane,hexane, isooctane, decane, toluene, xylene, and the like. Alternatively,the polymerization may be conducted using substantially pure monomers,e.g., ethylene and/or propylene. In a process which uses a refinery orsteam cracker feedstream, the feedstream containing the olefinic monomerto be polymerized, e.g., 1-butene, typically contains certain amounts ofother C₄ hydrocarbons. More particularly, the feedstream can compriseless than 5 weight percent isobutylene, at least 12 weight percent totaln-butenes (i.e., 1-butene and 2-butene), and less than 1 weight percentbutadiene, together with n-butane and isobutane. When used to preparethe POH copolymer, a preferred C₄ feed stream comprises spent C₄ streamsproduced as by-product in the manufacture of polyisobutylene, whereinthe C₄ streams produced as by-product in the manufacture ofpolyisobutylene, wherein the C₄ feedstream (often referred to asRaffinate II) contains less than 5 weight percent isobutylene, 10 to 70weight percent saturated butanes and 15 to 85 weight percent 1-buteneand 2-butene. The saturated butanes function as a diluent or solvent inthe reaction mixture. Typically the C₄ feedstream is maintained at asufficient pressure to be in the liquid form both at the reactor inletand in the reaction mixture itself at the reaction temperature. Inaddition to the olefinic feedstream component there is required a polarmonomer feed component as defined above. The polar monomer can bediluted, used neat and, alternatively, can be fed as a separatefeedstream or mixed with the olefin feedstream. The amount of polarmonomer fed to the reactor will depend on the efficiency of polarmonomer incorporation in the copolymer for the particular catalystsystem employed and the level of polar monomer desired in the copolymer.These aspects can be readily determined by one skilled in polymerizationart.

The preferred reaction process of the present invention is continuous,employs a dilute feed, and is operated to achieve a high level ofmonomer conversion. For purposes of this invention “continuous” meansthat a feed stream containing the olefinic monomer is continuouslyintroduced into the reaction zone and resultant POH copolymer product iscontinuously withdrawn.

The advantages of employing a highly diluted monomer feed are describedabove. For the purposes of the present invention, the diluent can be anynon-reactive (under the conditions employed) material which preferablyis capable of : (i) being liquefied under reaction conditions; (ii)dissolving at least the α-olefin monomer where one is employed; and(iii) dissolving or at least suspending the copolymer product underreaction conditions such that viscosity buildup is sufficientlyminimized to the extent that the mass transfer rate of the olefin, andethylene in particular, needed to homogeneously distribute olefinthroughout the reaction zone is at least equal to and preferably isgreater than, the reaction rate at which olefin is consumed in thepolymerization reaction. Suitable but less preferred diluents includesuch solvents as alkanes, aromatic hydrocarbons, and nonreactivealkenes. It is contemplated that the non-reactive diluents comprisetypically at least 30, preferably at least 40, and most preferably atleast 50 weight % of the α-olefin feed stream and the diluent can rangetypically from 30 to 90 (for example from 35 to 75 weight %) preferablyfrom 40 percent to 80, and most preferably from 50 to 60 weight % of theα-olefin feed stream (where ethylene is used as a comonomer, the recitedlevels refer to concentrations before admixture with ethylene).

It is a particular advantage of the present invention that the preferredmonomer feedstream comprises preferred diluents which are present invarious refinery or steam cracker streams containing α-olefin monomerreactants; to be useful such streams must contain at least one α-olefinas the reactive constituent. However, these streams typically willcontain non-reactive constituents which have a similar carbon number tothe α-olefin. The similarity in carbon number causes the non-reactiveconstituents to have similar boiling points to the α-olefin.Consequently, the non-reactive constituents will vaporize together withthe α-olefin and not only dilute the α-olefin in the vapor space, butalso, where used, ethylene comonomer. This dilution effect decreases themass transfer resistance of the reactive monomers in the vapor space,particularly ethylene.

Accordingly, a preferred diluent will contain components comprisingtypically at least 50, preferably at least 75, and most preferably atleast 95 weight %, and typically from 50 to 100, preferably from 75 to100, and most preferably from 95 to 100 weight % thereof, having aboiling point at the reaction conditions of typically within ±20° C.,preferably within ±15° C., and most preferably within ±10° C. of theaverage boiling point of the α-olefin constituents of the feed.Representative of such refinery or steam cracker streams are those whichcontain butene-1, propylene or C₅ α-olefin. Preferred butene-1containing streams are referred to herein as Raffinate-2 streams. Suchstreams typically have isobutylene content significantly lowered inrelation to the stream from which they are derived. Raffinate-2 istypically derived from either butane/butene catalytic cracking orrefinery streams (BB-streams) or Raffinate-1 which, in turn, is derivedfrom butadiene crude produced by steam cracking plants. The compositionof Raffinate-2 can vary widely, depending upon the source, e.g., (weight%):

Raff-2 Raff-2 Crude From From Component Butadiene Crude BB BB Raff-1Butadiene 43.5 ± 20   0-5  0.3 ± .15  0.4 ±  0.1 ± .05  0.2 Isobutylene25.2 ± 10   0-5 12.6 ± 6  0.2 ± 44.6 ± 20  0.1 Butene-1 15.5 ± 8 49.5 ±13.6 ± 6 15.4 ± 27.4 ± 15 25  7 cis-Butene-2  2.0 ± 1  6.4 ±  9.0 ± 410.2 ±  3.5 ± 1.5  3  5 trans-Butene-2  6.2 ± 3 19.6 ± 13.8 ± 6 15.6 ±10.9 ± 5 10  7 n-Butane  4.6 ± 2 14.7 ± 10.5 ± 5 12.0 ±  8.1 ± 4  7  6Isobutane  2.9 ± 1.5  9.4 ± 36.7 ± 15 42.1 ±  5.2 ± 2.5  4 20 Other* 0.1 ±  0.2 ±  0.2 ± 0.1^((b))  3.5 ± 1.5  0.5^((a))  4.1 ± 2  0.1*Other: ^((a))includes propane, propene, pentanes, pentenes, water,trace other hydrocarbons. ^((b))Raffinate-2 derived from MTBE production(using BB-stream or Raffinate-1) will include traces of MTBE, methanol,di-methyl ether, and tert-butyl alcohol.

Typical commercially available butene-1 concentrations in Raffinate-2range from about 15 to about 55 weight %. The above butene-1-containingrefinery or steam cracker streams are preferred for making POHhomopolymer or copolymers containing, e.g., ethylene. The instantinvention may also make use of BB streams and Raffinate-1 directly,since isobutylene is almost entirely unreactive in the presence of thelate-transition-metal catalyst systems. Hence, depending upon shippingcosts, convenience, or whatever other factors may affect thedecision-making process, one skilled in the art has the option of eitheracquiring Raffinate-2 and running it through the process of the instantinvention or first acquiring either Raffinate-1 or a BB stream, runningit through the process, and then shipping the resultantisobutylene-enriched stream to an MTBE plant or other end use. The useof Raffinate-2 is preferred. The use of crude butadiene streams directlyis not desired since it would waste butadiene which is hydrogenatedprior to polymerization. While it is preferred, it is not required thatrefinery or steam cracker streams be used and, in fact, it iscontemplated that dilute α-olefin containing streams can be prepared byseparately combining pure α-olefin and one or more pure diluents, e.g.pure isobutane, such as those typically found in the above refinery orsteam cracker streams. If the latter approach is followed, the level ofdiluent should be based on the teachings herein in order to achieve theadvantages of the process disclosed.

It will also be seen that this invention is useful in the production ofseveral POH copolymers and copolymers and may therefore be used in theprocessing of other dilute refinery or steam cracker streams, such asdilute propene and pentene streams common in the industry. Diluterefinery or steam cracker propene streams, known in the industry as “C₃streams”, and dilute refinery or steam cracker pentene streams, known as“C₅ streams”, are also derived from steam and catalytic cracking andgenerally can be represented to comprise the following components(ranges, weight %): For C₃ streams: Propylene=55±20; Propane=34±15;Ethylene=2±1; Ethane=8 ±4; and Other=1±5 (Other includes methane,acetylenes, propadiene, trace C₄'s and C₅'s, and trace polar compoundssuch as water, carbonyl sulfide, methyl mercaptan, and hydrogensulfide). For C₅ streams composition is more complex than that of C₃ andC₄ streams:

Component Range (wt. %) Component Range (wt. %) 2-methyl-Butene-1  9.0 ±4 n-Pentane 5.5 ± 2 3-methyl-Butene-1  1.6 ± 1 Cyclopentane 0.6 ± .3Pentene-1  5.1 ± 2 Cyclopentene 1.5 ± .75 2-methyl-Butene-2 14.9 ± 7Piperylene 0.9 ± .4 Pentene-2 15.4 ± 7 C₆ Olefins 1.5 ± .75 Isoprene 0.7 ± .3 C₆ Alkyls 3.5 ± 1.5 Isopentane 36.2 ± 15 C₇'s and C₈'s 2.0 ± 1Others*  1.6 ± 1 *Others include benzene and polar compounds.

Pentene-1 and cyclopentene are the most reactive components of a C₅stream in the presence of a late-transition-metal catalyst system andare readily separated from each other by distillation and concentrated.

Whether a constituent, e.g. of the refinery or steam cracker stream,qualifies as a diluent under reaction conditions depends on whether itis non-reactive which in turn depends on the specific catalyst and typeof pretreatment to which the feed is subjected. “Non-reactive” when usedin conjunction with diluent is meant that less than 5 wt. %, preferablyless than 3 wt. %, and most preferably less than 1 wt. % of theconstituent present in the feed is incorporated into the copolymerproduct and the constituent does not totally deactivate thelate-transition-metal catalyst system. Typically, any saturatedhydrocarbon constituent will quality as diluent as well as unsaturatedconstituents such as butene-2 and isobutylene which are highlyunreactive in the presence of a late-transition-metal catalyst system.Materials such as butadiene tend to deactivate the catalyst. Hence, itis preferred that they be removed or at least partially saturated byhydrogenation. Once saturated, the butadiene becomes part of the diluentas butane, butene-2, or a polymerizable α-olefin, butene-1.

The process of the invention is controlled to achieve high ethylene andα-olefin conversion. Conversion is directly proportional to monomerconcentration, catalyst concentration and residence time. Accordingly,these parameters are controlled to achieve an ethylene conversion oftypically at least 70%, preferably at least 80%, and most preferably atleast 90% and can arrange typically from 70% to 100%, preferably from80% to 100% and most preferably from 90% to 100% (e.g., 90-95%). Theα-olefin conversion is controlled to be typically at least 30%, e.g., atleast 40%, preferably at least 50%, and most preferably at least 60% andcan range typically from 30% to 95%, preferably from 50% to 90% and mostpreferably from 50% to 90%. Monomer conversion (%) can be determined byeither of the following equations:${= {\frac{\text{wt/hr of monomer incorporated into copolymer}}{\text{wt/hr of monomer in feed}} \times 100}}\quad;\quad {{or} = {\frac{\text{wt/hr monomer in feed} - \text{wt/hr monomer not reacted}}{\text{wt/hr~~monomer in feed}} \times 100}}$

Where a mixed olefin feed is used, e.g., and α-olefin in combinationwith ethylene, the particular α-olefin conversion employed depends inpart on the apparent ethylene content sought to be imparted to thecopolymer and hence on the ethylene concentration in the mixed feed. Forexample, at low ethylene content the α-olefin conversion typically willbe lower than for high ethylene content feeds. While high conversion canbe achieved by any combination of process conditions affectingconversion, it is preferred to maintain a low catalyst concentration andlow monomer concentration and attain high conversion with a longresidence time. Where ethylene is used as a comonomer, preferably theethylene conversion is controlled in a manner such that the ratio of theweight % of ethylene in the vapor phase to the weight % of ethylene inthe reactant feed stream is typically not greater than 1.2:1, preferablyless than 1:1 and most preferably from 0.1:1 to 0.7:1 (e.g., 0.1:1 to0.5:1). The monomer in the reaction mixture is kept low through the useof the diluent in the feed and operating at high conversions.

The catalyst concentration is typically held just above the poison leveldue to cost of the catalyst. Preferably the feed is treated to removemost if not all catalyst poisons, but this can vary depending on thesensitivity of the particular catalyst system to the presence ofpoisons. Minor poison contamination can be accommodated by increasingthe catalyst system concentration with the excess used to remove thepoison by reaction therewith. Accordingly, while any effective catalystconcentration can be employed, it is contemplated that such effectiveamounts will be sufficient to achieve a weight ratio oflate-transition-metal catalyst system to copolymer product of typicallyfrom 1×10⁻⁶:1 to 1×10⁻¹:1.

The residence time is determined from the following equation:${{Residence}\quad {time}} = \frac{\text{total true volume of liquid in reactor}}{\text{total volume/time of liquid exiting reactor}}$

wherein gas bubble volume in the liquid is subtracted from apparentvolume of liquid in reactor to obtain true volume. Accordingly,residence times can vary from typically, about 0.1 to about 5 hrs.;preferably from about 0.5 to about 4 hrs.; and more preferably fromabout 1 to about 3 hrs.

Reaction temperature and pressure are preferably controlled to liquefythe diluent and α-olefin. However, when ethylene is present, thereaction temperature is typically selected to be above the criticaltemperature of ethylene but below the critical temperature of theα-olefin feed and/or diluent. Accordingly, while any effectivetemperature can be employed in order to produce the POH copolymer of thedesired Mn in an efficient manner, it is contemplated thatpolymerization will generally be conducted at temperatures of from about0° C. to about 300° C.; preferably from about 10° C. to about 200° C.;for a feed containing butene-1 such effective temperatures will rangetypically from about 10° C. to about 150° C., preferably from about 15°C. to about 120° C., and most preferably from 25° C. to about 110° C.For the dilute refinery or steam cracker streams of propylene havingpropane as the major diluent, the critical temperature of propylene andpropane are 92.42° C. (198.36° F.) and 96.7° C. (206.06° F.)respectively, so the typical range of reaction temperatures would be 10to 96, and preferably from 25 to 92° C. The critical temperature of thefeed components in the reactor places an upper limit on temperature whenusing a boiling reactor since the reflux mechanism becomes useless ifnearly all or all of the feed flashes into the reactor vessel and thereremains no liquid phase to reflux. In less preferred embodiments, theoperation above the critical temperature of the major reactorconstituents must be compensated for by assisting or eliminating thereflux mechanism altogether and relying on alternative cooling means,such as jacketed reactor cooling or internal reactor cooling coils.Neither of these solutions is as effective nor as efficient as refluxcooling in maintaining homogeneity of temperature throughout thereaction solution. As indicated above, the boiling reactor representsthe preferred method for temperature control. Variations on the boilingreactor configuration include internal reflux, e.g. using cooling coilsinserted into the vapor space or an external system wherein vapor isremoved from the vapor space and introduced to an external refluxapparatus, the vapor condensed and the condensate returned to thereactor and/or feed. Alternative non-reflux temperature control meansinclude pumparound cooling where liquid is removed from the reactor,cooled, and then returned to the reactor. Pumparound cooling offers theadded advantage of being able to return cooled liquid to the reactorusing high pressure pumps to also provide mixing of reactor contentswith high speed jets.

Reactor pressures are typically controlled to maintain the diluent andα-olefin in liquid form at the selected temperature. In boiling reactorsthe pressure is selected to obtain boiling of the diluent/α-olefinreactor constituents at the reaction temperature. Accordingly while anyeffective pressure can be employed it is contemplated that where, e.g.,a feedstream containing butene-1 is used, such effective pressures willrange typically from about 2.4 to about 39 atm., preferably from about4.4 to about 28 atm., and most preferably from about 5.6 to about 23.5atm.

The reaction mixture is preferably vigorously mixed by any suitablemeans such as impeller, jet pump, or vigorous boiling or combinationsthereof. Baffles and strategic placement of feed input can be employedto further facilitate mixing. While conducting the polymerization, thereis preferably sufficient mixing in the reactor in order to providesubstantial homogeneity and where more than one monomer is used, e.g.,ethylene and an α-olefin, sufficient mixing to avoid the production ofhomopolymer of one or both of the monomers, or a compositionallynonuniform copolymer. More particularly, when two or more monomers areused, it is preferred that the monomers together enter a turbulent zoneinside the reactor. This can be accomplished in a stirred reactor, forexample, by placing all of the all monomer feed inlets near to eachother and near the impeller blade. As described herein, mixing is alsofacilitated by the use of a dilute pre-mixed feed stream from a refineryor steam cracker. Sufficient mixing in the reactor promotes the randomincorporation of each monomer unit in a growing copolymer chain,resulting in copolymers of relatively homogeneous composition (bothinter-chain and intra-chain) and relatively short sequences of any onemonomer, e.g., ethylene (i.e., low ESL values), compared to analogouscopolymers produced without such mixing. Analogously, sufficient mixingprovides an opportunity to randomize the structure of the POH copolymereven where a single olefinic monomer is used by facilitating mass andheat transfer involving both the catalyst components and the monomers.Effective mixing is especially important to the production of copolymersof the invention having a high concentrative of one monomer in amulti-monomer polymerization process (i.e., above 35 weight percent),because, without such mixing, the resulting copolymer could havesufficient monomer sequences to increase the probability ofcrystallinity, e.g., ethylenic crystallinity in an ethylene copolymerderived from ethylene or another α-olefin, in combination with a polarmonomer, e.g., as manifested by ESL values above 2.50.

When carrying out the polymerization in a batch-type fashion, thereaction diluent (if any), and the monomers are charged at appropriateconcentration and ratios to a suitable reactor. Care should be takenthat all ingredients are dry, with the reactants typically being passedthrough molecular sieves or other drying means prior to theirintroduction into the reactor. Although certain of thelate-transition-metal catalysts of this invention may be lesssusceptible to moisture and other poisons than catalysts such asZiegler-Natta and metallocenes, it is preferred that the catalyst systembe of uniform composition and quality in order to reduce variations inthe process and the resulting POH copolymer, e.g., its molecular weightand/or MWD. Subsequently, either the catalyst and then the cocatalyst,or first the cocatalyst and then the catalyst are introduced whileagitating the reaction mixture, thereby causing polymerization tocommence. Alternatively, the catalyst and cocatalyst may be premixed ina solvent and then charged to the reactor. As copolymer is being formed,additional monomers may be added to the reactor. Upon completion of thereaction, unreacted monomer and solvent are either flashed or distilledoff, if necessary by vacuum, and the copolymer of suitable molecularweight withdrawn from the reactor.

Copolymer Characteristics

Employing a late-transition-metal catalyst system in accordance with theprocedures and under the conditions as described herein results in a POHcopolymer having a high degree of terminal unsaturation, e.g., vinyland/or vinylene group terminating at least about 30% of the copolymerchains. In contrast, prior art polymers or copolymers produced using ametallocene catalyst system were generally incapable of copolymerizing asignificant amount of polar monomer and also resulted in terminallyunsaturated olefinic polymers exhibiting a high concentration ofvinylidene type unsaturation relative to vinyl type unsaturation, e.g.,at least 3.5 to 1; this translates to about 22% vinyl. (see WO 90/1,503)The POH copolymer chains can be represented by the formula POLY—CH═CH₂or POLY—CH═CH—R wherein POLY represents the copolymer chain (includingthe incorporated polar monomer moiety which is generally present at theterminal position of a branch), —CH═CH₂ represents a vinyl groupterminating one end of the chain and —CR′═CH—R represents a vinylenegroup, terminating one end of the chain, wherein R represents an alkylgroup such as methyl, ethyl, etc., and R′ represents H or an alkyl groupsuch as methyl, ethyl, etc. The POH copolymers typically have vinyland/or vinylene groups terminating at least about 30 percent of thecopolymer chains (although typically, the opposite ends of the samecopolymer chain do not each contain an unsaturated structure);preferably, at least about 50 percent, more preferably about 75 percent,still more preferably at least about 80 percent, and most preferably atleast about 90 percent of the copolymer chains; typically from about 30to about 95 percent, preferably from about 50 to about 90 percent, morepreferably from about 75 to about 90 percent of the copolymer chainsbeing so terminated. In addition, the copolymers typically havevinylidene groups (i.e., POLY—C(—CH₂CH₃)═CH₂, where —C(CH₂CH₃)═CH₂ isethylvinylidene), terminating no more than 15 percent of the chains;e.g., from about 0 to about 15 percent; preferably from about 2 to about10 percent. Trisubstituted olefinic groups can also be present in minoramounts, for example, no more than 15 percent of the chains; e.g., fromabout 0 to about 15 percent; preferably from about 0 to about 10percent. The predominance of vinyl and vinylene terminal olefinicstructures differs significantly from the predominantly terminalvinylidene structures resulting from metallocene catalyzedpolymerizations of ethylene α-olefin copolymers. The percentage ofcopolymer chains exhibiting terminal vinyl, vinylene, vinylidene, etc.unsaturation, may be determined by C-13 NMR. It will be understood thata change in the type of late-transition-metal catalyst and/orco-catalyst or activator used to prepare the copolymer can shift theabove described double bond distribution to some extent. Because of therelatively high level of terminal vinyl and vinylene unsaturation in thePOH copolymers, the dispersant additives produced therefrom haveparticularly high active ingredient concentrations, thereby providingenhanced lubricating oil dispersancy, which can be exhibited as enhancedsludge and varnish control properties.

The copolymers of this invention, particularly those intended for use indispersant applications, typically have a number average molecularweight (M_(n)) of from about 300 to about 10,000; preferably from about700 to about 5,000 (e.g., 1,000-5,000), more preferably from about 700to about 2,500 (e.g., 1,500 to 2,500) and most preferably from about 750to about 2,500. When lower molecular weight copolymers are used in waxcrystal modified applications their Mn is up to about 15,000, e.g., fromabout 500 to about 15,000. Higher molecular weight copolymers of theinvention that are oil soluble also find utility in lube oil flowimprover and viscosity modifier applications, as well as wax crystalmodifiers. For example, useful higher molecular weight copolymers andcopolymers have Mn of from about 15,000 to about 500,000; preferablyfrom about 30,000 to about 300,000; more preferably from about 45,000 toabout 250,000 e.g., from about 50,000 to about 150,000. Typically,selection of molecular weight in viscosity modifier applications iscontrolled by shear stability requirements of the contemporarymarketplace.

The POH copolymers of this invention preferably exhibit a degree ofcrystallinity such that they are essentially, and substantially,amorphous.

The nature of the catalyst system employed in this invention can resultin a phenomenon referred to as “chain straightening,” producingcopolymer chains having monomer sequences which appear to have beenderived from ethylene monomer (for the sake of convenience, sometimesreferred to herein as “apparent” ethylene content), even in thosecircumstances in which ethylene monomer is not, in fact, employed in thepolymerization. Conversely, the use of ethylene monomer alone in thepresence of the recited catalyst system results in chain branching, thusgiving the appearance of the use of a higher alkyl comonomer, e.g.,propylene, even when none is used. (In comparison, the polymerization ofethylene using a Ziegler-Natta or metallocene catalyst system typicallyresults in less than one branch per hundred carbon atoms as a result of“defective” monomer insertion.) Similarly, in the present invention,polymerization of 1-butene leads to substantial incorporation of linearmethylene sequences and a distribution of amorphous chain branches;polymerization of the olefins described leads to branch lengthspreferably of from C₁-C_(n), where n is typically 1 to 4.

The α-olefin that is polymerized and the extent and type of branchingshould be controlled for copolymers intended for use in lubricant andfuel applications. For dispersant and lower molecular weightapplications, the olefin is preferably at least one selected from C₂-C₈monomers (i.e., ethylene and C₃-C₈ α-olefin); more preferably C₂-C₆;most preferably C₂-C₄ olefinic monomers. Very long chain branchingshould be avoided because dispersancy in, e.g., gasoline engineapplications is related to the hydrodynamic volume of the copolymerchain. Incorporating most of the molecular weight of the copolymer intothe backbone is preferred; hence typically at least about 50% of thebranches should be methyl and/or ethyl (C₁ or C₂) and at least about 80%of the branches should be C₁-C₄; preferably at least about 75% should beC₁-C₂ and 85% should be C₁-C₄; more preferably at least about 90% shouldbe C₁-C₂ and 95% should be C₁-C₄; most preferably at least about 95% ofthe branches are C₁-C₄ branches.

The POH copolymers of the present invention provide a uniquelystructured backbone for producing the additives of interest. Prior artpolymers and copolymers produced using Zielger-Natta or metallocenecatalyst systems typically contained branches whose length wasessentially determined by the monomer which was polymerized; e.g.,polymerization of propylene resulted in a copolymer containing almostexlusively methyl branches (the exceptions being introduced byincorporating “errors” during polymerization). In contrast, as notedabove, the POH copolymers of the present invention contain adistribution of branch lengths which typically result from thepolymerization of each monomer or combination of monomers. Thedistribution of branch lengths results in copolymers whose solutionproperties, response to temperature and waxinteraction/cocrystallization response differs from the prior art. Thesecharacteristics can be tuned in order to achieve a balance notpreviously available. Generally, catalyst and process features areselected in order to reduce long ethylene sequences in the copolymerbackbone and introduce additional branches. This is preferablyaccomplished by using a Ni-based catalyst and conducting thepolymerization at a lower temperature.

Conversely, too little chain branching can lead to insolubility in oiland potential problems with pour point properties. Sufficient chainbranching is required so that long, uninterrupted methylene sequences,which are capable of crystallizing at low temperatures and interferingwith oil solubility are avoided. Controlled branching an controlledco-crystallization is advantageous in order to modify wax crystal growthin fuel oils so as to optimize such performance in that application.Typically, there should be, on average, at least about 5 branches per100 carbon atoms, i.e., from about 10 to about 33, for example fromabout 15 to about 30 branches per 100 carbon atoms of copolymer. Invarious applications the number of branches is preferably from about 11to about 25 per 100 carbon atoms; more preferably from about 12 to about20; most preferably from about 13 to about 16; for example, usingcopolymers are produced having from about 10 to about 12.5 branches per100 carbon atoms present in the copolymer chains. In the presentinvention additional control means are available at the “copolymerdesign” level to control the copolymer structure so that it best suitsthe particular application. For example, in those applications where theextent of branching would be too great using an α-olefin monomer as theonly polymerizable olefin, ethylene can be employed as a comonomer. Inthis manner additional straight chain segments or methylene sequencescan be introduced but, since ethylene polymerized using the catalystsystem herein also introduces branches, its use would not introduce,e.g., pour point problems.

For the purposes of the purposes of the present invention in dispersantapplications, the POH copolymer will typically contain not greater than50 weight percent monomer triad sequences which appear to beethylene-monomer centered, based upon the total copolymer weight;preferably not greater than 45; and most preferably not greater than 40weight percent of such apparent ethylene monomer sequences based uponthe total copolymer weight. Thus, the apparent ethylene content canrange typically from 1 to 50 (e.g., from 5 to 50) weight percent,preferably from 5 to 45 (e.g., 5 to 40) weight percent, and mostpreferably from 10 to 40 (e.g., 10 to 35) weight percent. One canreadily calculate the equivalent mole % values for recited ranges basedon the particular α-olefin that is used during the polymerization,either alone or in combination with ethylene, for dispersantapplications which preferably employ a C₃-C₈ α-olefin. For example, 50weight % ethylene in the presence of C3 monomer sequences converts to 60mole % ethylene, but in the presence of C8 monomer sequences converts to80 mole %. Similarly, the corresponding values can be calculated forother monomer combinations. For the use of the POH copolymers of theinvention as wax crystal modifiers for middle distillate fuels such asdiesel fuels and oils such as heating oils, typical ethylene contentwould be from about 70 to about 90 mole %; preferably from about 74 mole% to about 84 mole %. When used as a viscosity modifier, the copolymercan be produced using ethylene, C₃-C₂₀ α-olefins and mixtures thereof.Copolymers of suitable molecular weight typically contain from about 50mole % apparent ethylene derived sequences to about 78 mole percent fora copolymer containing apparent C₃ derived sequences and from about 87mole % to about 96 mole percent ethylene for a C₂₀ derived copolymer.(These ranges correspond to 40 to 70 weight %; a more preferred range isfrom about 45 to about 60 weight percent apparent ethylene sequences.)

The copolymers of this invention may optionally contain small amounts,e.g., typically up to 10, preferably up to 5 weight percent, of unitsderived from other α-olefins and C₄ to C₂₂ diolefins. For example,introduction of small amounts of C₄ olefins other than butene-1 canresult during the preparation of the POH copolymers through the use of1-butene monomer feed streams which also contain limited amounts of2-butene, isobutene, and/or butadiene; similarly, limited amounts ofpolymerizable monomers may be present in refinery or steamcracker-derived C₃ and C₅ streams.

The POH copolymers of the invention typically also have an averageethylene sequence length (ESL) of from about 1.0 to less than about 3.0;preferably from about 1.0 to about 2.5; more preferably from about 1.0to about 2.0; for example from about 1.0 to about 1.5. ESL is the ratioof the total number of ethylene units in the copolymer chains to thetotal number of discrete ethylene sequences n the copolymer chains, asgiven by the following equation:

ESL=(X _(EEE) +X _(REE+EER) +X _(RER))/(X _(RER)+0.5*X _(REE+EER))

wherein X_(EEE) is the mole fraction of ethylene-ethylene-ethylene triadsequences in the copolymer; X_(REE+EER) is the mole fraction of higheralkyl, R, such as butene, e.g., butene-ethylene-ethylene andethylene-ethylene-butene triad sequences; and X_(RER) is the molefraction of the higher alkyl, R, such as butene-ethylene-butene triadsequences. The ethylene sequences can be present as a result of theα-olefinization of ethylene with an α-olefin or, as a result of the useof the late-transition-metal catalyst, “chain straightening” whichoccurs when polymerizing one or more α-olefins, resulting in thepresence of a higher alkyl, R, in the copolymer chain. The ESL value isan index reflecting the distribution of the units derived from ethyleneor resulting in ethylene sequences (and therefore apparently derivedfrom ethylene) in the POH copolymer chains. As the value for ESLincreases for a given POH copolymer of fixed ethylene content (actual orapparent), the number of isolated ethylene units in the chains declines,and, concomitantly, the number of ethylene units per ethylene sequenceincreases. Naturally, as the ethylene content increases in an POHcopolymer containing even a random distribution of ethylene units, thegeneral tendency is to obtain increased ESL values. As per the aboveequation, the ESL value of a copolymer can be calculated from X_(EEE),X_(REE+EER), and X_(RER), where R is, for example, butene, which valuesare determined from the copolymer's C-13 NMR spectrum, using the methodsdescribed in, for example, Randall, James C., Journal of MacromolecularScience—Reviews of Macromolecular Chemistry and Physics, C29, 201-317(1989). Alternatively, and as an approximation, one can use the integralof the “polymethylene” peak at 29.9 ppm and compare the value obtainedto the total aliphatic or methyl integral.

The POH copolymers of this invention preferably also have a molecularweight distribution (MWD), defined as the ratio of the weight averagemolecular weight (Mw) to the number average molecular weight (i.e.,MWD=Mw/Mn), of less than about 5, preferably less than about 4, and mostpreferably less than about 3. More specifically, the copolymers have amolecular weight distribution of from about 1.0 to about 3.5, and mostpreferably from about 1.1 to about 3. It will be appreciated by oneskilled in the art that the MWD of the copolymer is broadened byvariations of temperature, monomer concentration, and catalystconcentration and the specific level will be affected by the specificprocess conditions selected and the specific catalyst system employed.Both M_(n) and M_(w) can be determined by the technique of gelpermeation chromatography (GPC) with a suitable calibration curve, fromwhich MWD can be readily obtained. M_(n) and MWD for ethylene-α-olefincopolymers, for example, can be obtained using calibration curves basedupon polydisperse ethylene-α-olefin copolymers having ethylene contentssimilar to that of the samples under test. For a description of thedetermination of M_(n) and MWD using GPC (also known as size exclusionchromatography), see W. W. Yau, J. J. Kirkland and D. D. Bly, “ModernSize Exclusion Liquid Chromatography”, John Wiley and Sons, New York,1979. M_(n) can alternatively be determined for certain copolymers suchas ethylene-α-olefin copolymers from either their proton- or carbon-13NMR spectra obtained in solution, using conventional analyticaltechniques known to those skilled in the art. See, for example, “C13-NMRin Polymer Quantitative Analyses,” J. C. Randall and E. T. Hiseh, in:NMR and Macromolecules, Sequence, Dynamic, and Domain Structure, ACSSymposium Series No. 247, 131-151 (American Chemical Society, 1984).

Further Functionalization and Derivatization of the Copolymer

The copolymers produced in accordance with the present invention can beconsidered to be functionalized as a consequence of the presence of thepolar moiety, i.e., having at least one functional group present with inits structure, which functional group is capable of: (1) undergoingfurther chemical reaction (e.g., derivatization) with other material/or(b) imparting desirable properties, not otherwise possessed by anolefinic homopolymer or copolymer alone, absent the presence of a polarmoiety. However, the copolymer of the present invention also hasolefinic unsaturation present in its structure, preferably in the formof a terminal vinyl group, and such unsaturation is capable of beingfurther modified or further functionalized. Additionally, the functionalgroup can be incorporated into the backbone of the copolymer, or can beattached as a pendant group from the copolymer backbone. The functionalgroup typically will be polar and contain hetero atoms such as P, O, S,N, halogen and/or boron. It can be attached to the saturated hydrocarbonpart of the copolymer via substitution reactions or to an olefinicportion via addition or cycloaddition reactions. Alternatively, thefunctional group can be incorporated into the copolymer by oxidation orcleavage of a small portion of the end of the copolymer (e.g. as inozonolysis).

The function of dispersants is to maintain materials which are insolublein oil (and which result from oil use) in suspension in the fluid thuspreventing sludge flocculation and precipitation. Suitable dispersantsinclude, for example, dispersants of the ash-producing (also known asdetergents) and ashless type, the latter type being preferred. Thederivatized copolymer compositions of the present invention, can be usedas ashless dispersants and multifunctional viscosity index improvers inlubricant and fuel compositions. Generally, a copolymer containing areactive moiety, with or without further functionalization, is mixedwith at least one amine to form dispersant additives.

The copolymer of the invention polymer can be used as a dispersant ormultifunctional viscosity modifier if the latter also contains a groupcapable of performing the requisite dispersancy function. The copolymeras synthesized contains ethylenic functionality as well as a residue ormoiety from the polar comonomer. In addition, the copolymer can bemodified to introduce other functional groups to enable the copolymer toparticipate in a variety of derivatizing chemical reactions. Thesederivatized copolymers can have the requisite properties for a varietyof uses including use as dispersants and viscosity modifiers. For thepurposes of this disclosure a derivatized copolymer is one which hasbeen chemically modified to perform one or more functions in asignificantly improved way relative to the unfunctionalized copolymerand/or the functionalized copolymer. Representative of such functions,are dispersance and/or viscosity modification in lubricating oilcompositions.

The derivatizing compound typically contains at least one reactivederivatizing group selected to react with the reactive or functionalgroups of the copolymer by various reactions. Representative of suchreactions are nucleophilic substitution, transesterification, saltformation, and the like. The derivatizing compound preferably alsocontains at least one additional group suitable for imparting thedesired properties to the derivatized polymer, e.g., polar groups. Thus,such derivatizing compounds typically will contain one or more groupsincluding amine, hydroxy, ester, amide, imide, thio, thioamido,oxazoline, or carboxylate groups or form such groups at the completionof the derivatization reaction. Additionally, the functionalizedcopolymer can be reacted with basic metal salts to form metal salts ofthe polymer; preferred metals are Ca, Mg, Cu, Zn, Mo, and the like.

Suitable properties sought to be imparted to the derivatized copolymerinclude one or more of dispersancy, multifunctional viscositymodification, antioxidancy, friction modification, antiwear, antirust,seal swell, and the like. The preferred properties sought to be impartedto the derivatized copolymer include dispersancy (both mono- andmultifunctional) and viscosity modification, primarily with attendantsecondary dispersancy properties. A multifunctional dispersant typicallywill function primarily as a dispersant with attendant secondaryviscosity modification.

While the techniques for derivatization and further functionalizationfor preparing multifunctional viscosity modifiers (also referred toherein as multifunctional viscosity index improvers or MFVI) are thesame as for ashless dispersants (see below), the functionality of afunctionalized copolymer intended for derivatization and eventual use asan MFVI will be controlled to be higher than functionalized copolymerintended for eventual use as a dispersant. This stems from thedifference in Mn of the MFVI copolymer backbone vs. the Mn of thedispersant copolymer backbone. Accordingly, it is contemplated that anMFVI will be derived from functionalized copolymer having typically upto about one and at least about 0.5 functional groups, for each 20,000,preferably for each 10,000, most preferably for each 5,000 for each1,000 Mn weight segment in the backbone polymer.

The derivatized copolymers include the reaction product of the POHcopolymer with an amine reactant to form oil soluble amides.

Derivatization by Amine Compounds

Useful amine compounds for derivatizing the POH copolymers of theinvention, with or without further functionalization of the copolymeritself, comprise at least one amine and can comprise one or moreadditional amine or other reactive or polar groups. Where the functionalgroup is a carboxylic acid, carboxylic ester or thiol ester, it reactswith the amine to form an amide. Preferred amines are aliphaticsaturated amines. Non-limiting examples of suitable amine compoundsinclude: 1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane;1,6-diaminohexane; polyethylene amines such as diethylene triamine;triethylene tetramine; tetraethylene pentamine; etc. (Aminederivatization of POH polymers and production of dispersants andlubricant additives therefrom can be carried out according to thegeneral teachings in WO 95/35329, published Dec. 28 1995; incorporatedherein for the purposes of U.S. prosecution).

Other useful amine compounds include: alicyclic diamines such as1,4-di(aminomethyl) cyclohexane, and heterocyclic nitrogen compoundssuch as imidazolines. Mixtures of amine compounds may advantageously beused. Useful amines also include polyoxyalkylene polyamines. Aparticularly useful class of amines are the polyamido and relatedamines.

For the preferred polyamine dispersant of this invention, the novelpreferred compositions allow the benefit of using higher molecularweight backbones without the limitation of low nitrogen content and thedebit of high viscosities.

Polyamines containing one primary amino group and 1-10 secondary ortertiary amino groups are particularly useful (Referred to herein as“Type I” amines). For lubricant applications, polyamines with 3-8secondary or tertiary amino groups are preferred. For fuel applicationspolyamines with 1-3 secondary or tertiary amino groups are preferred.These polyamines may optionally contain oxygen and sulfur atoms as partof the molecule. The amino groups and the oxygen and sulfur aregenerally separated from each other by hydrocarbylene groups containingfrom 1-6 carbons. The polyamines could contain heterocycles as part oftheir structure.

The preferred polyamines contain only one primary amine per molecule;they are also referred to hereinafter as “one armed polyamines”.However, as the number of nitrogen atoms in the polyamines increases,some branching could occur giving mixtures of polyamines containingprimarily one amino group with some molecules containing more than oneprimary amino group. To minimize the viscosity of the final product andmaximize the nitrogen content, polyamines with the least amount ofbranching are particularly preferred.

In general, these one armed polyamines belong to two groups: (1)nonvolatile and (2) volatile amines. Volatile one armed polyamines areconsidered those polyamines that can be distilled during a strippingstep of the process if any remain unreacted as free amine. Volatileamines can be used in large excess to facilitate the completion of thereaction in the shortest possible time since the unreacted amines can berecovered and reused. The stoichiometry of the nonvolatile amine islimited to about one primary amino group per carbonyl group to avoidresidual unreacted polyamine in the dispersant mixture.

One type of one armed polyamine can be represented by the formula:

H₂N(—R^(i)—NH—)_(z)—(—R^(ii)—A—)_(y)—R^(iii)

Wherein:

R^(i) and R^(ii) are hydrocarbyl groups of from one to six carbons;

R^(iii) is a hydrocarbyl group containing from one to 40 carbons or aheterocyclic structure containing N, and/or S, and/or O;

A is oxygen or sulfur;

z=1 to 10; and

y=0 to 1.

As used herein the term “hydrocarbyl” denotes a group having a carbonatom directly attached to the remainder of the molecule and havingpredominantly hydrocarbon character within the context of this inventionand includes polymeric hydrocarbyl radicals. Such radicals include thefollowing:

(1) Hydrocarbon groups; that is, aliphatic, (e.g., alkyl or alkenyl),alicyclic (e.g., cycloalkyl or cycloalkenyl), aromatic, aliphatic- andalicyclic-substituted aromatic, aromatic-substituted aliphatic andalicyclic radicals, and the like, as well as cyclic radicals wherein thering is completed through another portion of the molecule (that is, thetwo indicated substituents may together form a cyclic radical). Suchradicals are known to those skilled in the art; examples include methyl,ethyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl,eicosyl, cyclohexyl, phenyl and naphthyl (all isomers being included).

(2) Substituted hydrocarbon groups: that is, radicals containingnon-hydrocarbon substituents which do not alter predominantlyhydrocarbon character of the radical. Those skilled in the art will beaware of suitable substituents (e.g., halo, hydroxy, alkoxy, carbalkoxy,nitro, alkylsulfoxy).

(3) Hetero groups: that is, radicals which, while predominantlyhydrocarbon in character, contain atoms other than carbon present in achain or ring otherwise composed of carbon atoms. Suitable hetero atomswill be apparent to those skilled in the art and include, for example,nitrogen, particularly non-basic nitrogen, oxygen and sulfur. Ingeneral, no more than about three substituents or hetero atoms, andpreferably no more than one, will be present for each 10 carbon atoms inthe hydrocarbon-based radical. Polymeric hydrocarbyl radicals are thosederived from hydrocarbon polymers, which may be substituted and/orcontain hetero atoms provided that they remain predominantly hydrocarbonin character.

One method to prepare these one armed polyamines consists of stepwisereaction of known alcohols, mono or polyamines with acrylonitrilefollowed by hydrogenation. The following is a partial list of thesepolyamines:

Derivatization with amines can also be conducted using amines containingmore than one primary amino group, including polyamines, in combinationwith the use of chain-stopping or end-capping reactants to prevent gelformation (Referred to herein as “Type II” amines). (Aminederivatization of POH polymers using polyamines and production ofdispersants and lubricant additives therefrom can be carried outaccording to the general teachings in U.S. Ser. No. 338,287, filed Nov.10, 1994, continuation of U.S. Ser. No. 991,837, filed Dec. 17, 1992(now abandoned); incorporated herein for purposes of U.S. prosection). Aparticularly useful class of polyamines comprise bis(p-amino cyclohexyl)methane (PACM) and oligomers and mixtures of PACM with isomers andanalogs thereof containing on average, from 2 to 6 or higher (usually 3to 4) cyclohexyl rings per PACM oligomer molecule. The total nitrogencontent of the PACM oligomers will comprise generally from 8 to 16 wt.%, and preferably from 10 to 14 wt. %. The PACM oligomers can beobtained, e.g., by fractionation, or distillation, as a heaviesby-product or bottoms from the PACM-containing product produced by highpressure catalytic hydrogenation of methylene-dianiline.

Still another useful class of Type II amines are the poly-amido andrelated amines which comprise reaction products of a polyamine and analpha, beta unsaturated compound. Any polyamine, whether aliphatic,cycloaliphatic, heterocyclic, etc., (but not aromatic) can be employedprovided it is capable of adding across the acrylic double bond andamidifying with for example the carbonyl group of an acrylate-typecompound or with the thiocarbonyl group of a thioacrylate-type compound.

The hydrocarbyl groups of the alpha, beta unsaturated compound cancomprise alkyl, cycloalkyl, or heterocyclic, which can be substitutedwith groups which are substantially inert to any component of thereaction mixture under conditions selected for preparation of theamido-amine. Such substituent groups include hydroxy, halide (e.g., Cl,Fl, I, Br), —SH and alkylthio. When one or more of the hydrocarbylgroups are alkyl, such alkyl groups can be straight or branched chain,and will generally contain from 1 to 20, more usually from 1 to 10, andpreferably from 1 to 4, carbon atoms. Illustrative of such alkyl groupsare methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl,decyl, dodecyl, tridecyl, hexadecyl, octadecyl and the like. When one ormore are cycloalkyl, the cycloalkyl group will generally contain from 3to 12 carbon atoms, and preferably from 3 to 6 carbon atoms.Illustrative of such cycloalkyl groups are cyclopropyl, cyclobutyl,cyclohexyl, cyclooctyl, and cyclododecyl. When one or more areheterocyclic, the heterocyclic group generally consists of a compoundhaving at least one ring of 6 to 12 members in which one or more ringcarbon atoms is replaced by oxygen or nitrogen. Examples of suchheterocyclic groups are furyl, pyranyl, pyridyl, piperidyl, dioxanyl,tetrahydrofuryl, pyrazinyl and 1,4-oxazinyl.

Examples of the alpha, beta-ethylenically unsaturated carboxylatecompounds useful for reaction with the polyamine are acrylic acid,methacrylic acid, the methyl, ethyl, isopropyl, n-butyl, and isobutylesters of acrylic and methacrylic acids, and 2-butenoic acid.

Various types of alpha, beta ethylenically unsatuated compounds may beemployed, including:

(a) carboxylate thioester compounds; examples of these compounds aremethylmercapto 2-butenoate and ethylmercapto 2-hexenoate;

(b) carboxyamide compounds; examples of these compounds area2-butenamide and 2-hexenamide;

(c) thiocarboxyamide compounds; examples are 2-butenthioic acid and2-hexenthioic acid;

(d) dithioic acid and acid ester compounds; examples are 2-butendithioicacid and 2-hexendithioic acid; and

(e) thiocarboxyamide compounds; examples of these compounds are2-butenthioamide and 2-hexenthioamide.

Preferred compounds for reaction with the polyamines in accordance withthis invention are lower alkyl esters of acrylic and (lower alkyl)substituted acrylic acid. In the preferred embodiments these compoundsare acrylic and methacrylic esters such as methyl or ethyl acrylate,methyl or ethyl methacrylate. When the selected alpha, beta-unsaturatedcompound contains oxygen, the resulting reaction product with thepolyamine contains at least one amido linkage (—C(O)N<) and suchmaterials are herein termed “amido-amines.” Similarly, when the selectedalpha, beta unsaturated compound contains sulfur, the resulting reactionproduct with the polyamine contains thioamide linkage (—C(S)N<) andthese materials are herein termed “thioamido-amines.” Generally,equimolar amounts of polyamine and alpha, beta ethylenically unsaturatedcarboxylate yields a more linear amido-amine whereas an excess of alpha,beta unsaturated compound tends to yield an amido-amine which iscrosslinked. Preferably, the amido-amines are not crosslinked to asubstantial degree; more preferably they are substantially linear.

The reaction can be carried out at any suitable temperature, generallybelow 100° C., for example 80-90° C. Reaction time can vary from about 2to 30 hours; such as 5 to 25 hours; preferably 3 to 10 hours.

When the post-treating reactant comprises a polyfunctional compound,i.e. a compound containing more than one reactive group, it is necessaryto use sufficient chain-stopping or end-capping reactant in combinationwith the polyfunctional post-treating reactant to ensure that thederivatized product mixture will be gel-free.

The chain-stopping or end-capping reactants contemplated for use in thisaspect of the invention include monofunctional reactants which arecapable of reacting with reactive amine groups present in thepolyfunctional reactants of the Type II amines or with the polar moietyor reactive groups which are grafted or otherwise attached to the POHcopolymer to inhibit cross linking and gelation and/or viscosityincrease due to any further reaction of unreacted amino groups in theaminated or modified POH copolymer. Preferred chain-stopping orend-capping reactants include, for example, hydrocarbyl substituteddicarboxylic anhydride or acid, preferably succinic anhydride or acid,having from about 12 to 400 carbons in the hydrocarbyl group; long chainmonocarboxylic acid of the formula RCOOH where R is a hydrocarbyl groupof 12 to 400 carbons in the hydrocarbyl group; alcohol compounds havingonly a single hydroxy group per molecule; and amine compounds havingonly a single reactive amine group per molecule. The hydrocarbyl groupsare essentially aliphatic and include alkenyl and alkyl groups. Thelonger chain acids and anhydrides are preferred, particularly when thegrafting reaction is carried out in lubricating oil because of theirability to impart dispersancy to reacted oil molecules as well as theirgreater solubilizing effect. In one preferred embodiment, thechain-stopping or end-capping reactant comprises a C₁₂ to C₄₉hydrocarbyl substituted succinic anhydride, e.g. a C₁₂ to C₁₈hydrocarbyl substituted succinic anhydride. In other preferredembodiments, the hydrocarbyl substituent contains from 50 to 400 carbonatoms.

Primarily because of its ready availability and low cost, thehydrocarbyl portion, e.g. alkenyl groups, of the carboxylic acid oranhydride is preferably derived from a polymer of a C₂ to C₅ monoolefin,said polymer generally having a Mn of about 140 to 6,500, e.g. 700 to5,000, most preferably 700 to 3,000. Particularly preferred polymer ispolyisobutylene. Particularly preferred chain-stopping reactants includepolyisobutylene succinic anhydride wherein the Mn of the polyisobutyleneportion is from 700 to 2,500.

Alcohols having a single reactive hydroxy group per molecule useful aschain-stopping or end-capping reactants generally comprise from 4 to 8carbon atoms and include, for example, C₄-C₈ aliphatic alcohols such asbutanol, pentanol and hexanol. The use of alcohols having less than 4carbon atoms generally is to be avoided because of their low volatility.Alcohols having more than about 8 carbon atoms generally are to beavoided since it is difficult to remove unreacted higher molecularweight alcohols from the derivatized product and since the presence ofunreacted higher molecular weight alcohols in the product mixture canresult in dispersant additives having less favorable viscometricproperties.

The aforesaid post-treating, amine reactants having more than onereactive amino group and the chain-stopping or end-capping reactants maybe pre-reacted with the chain-stopping or end-capping reactant generallybeing attached to the post-treating reactant through salt, imide, amideamidine, ester, or other linkages so that a single reactive group of thepost-treating reactant is still available for reaction with the reactivemoieties of the POH copolymer. A convenient source of these prereactedmaterials are the well-known carboxylic acid derivatives such assuccinimides used as lubricating oil dispersants, provided they retainreactive amine and/or hydroxy groups capable of further reaction withthe POH copolymer.

The POH copolymer, with or without further functionalization, can bereacted with an individual amine reactant or such reactant andchain-stopping or end-capping reactant or any combination of two or moreof any of these reactants; that is, for example, one or moremonoreactive amines or polyamines, so long as sufficient monoreactivereactant is used when a reactant having more than one reactive group isused to ensure a gel-free reaction.

The reaction between the copolymer and the amine and/or chain-stoppingor end-capping reactants is readily accomplished, for example, byheating a solution containing 5 to 95 wt. percent of the copolymer in asubstantially inert organic solvent or diluent at from 100 to 250° C.,preferably 125 to 175° C., generally for 1 to 10, e.g., 2 to 6 hours.Suitable diluents include, for example, aliphatic, cycloaliphatic, andaromatic hydrocarbons, as well as the corresponding halogenatedhydrocarbons, particularly chlorinated hydrocarbons. These diluents areexemplified by benzene, toluene, chlorobenzenes, hexane, heptane, ormixtures of these. Mineral oils particularly low viscosity mineral oilsare very good diluents. Preferred diluents are mineral oils oflubricating viscosity.

Reaction ratios of copolymer to equivalents of amine reactant, andchain-stopping or end-capping reactants described herein, can varyconsiderably, depending, e.g., on the reactants and type of bondsformed. Generally, when an amine compound is reacted with a copolymer,from 0.05 to 4.0, preferably from 0.5 to 2.0, e.g., 0.6 to 1.5, moles ofpolar moiety content is used, per equivalent of amine reactant.

A preferred group of ashless dispersants, in accordance with the presentinvention, are those derived from POH copolymer reacted withpolyethylene amines, e.g., tetraethylene pentamine, pentaethylenehexamine, polyoxyethylene or polyoxypropylene amines, e.g.,polyoxypropylene diamine, and with polyisobutytene succinic anhydridechain-stopping reactant. Another preferred group of ashless dispersantsare those derived from POH copolymer reacted with monofunctionalheterocyclic amines, e.g., N-(3-aminopropyl)morpholine.

Supplemental or further functionalization of the copolymer withfunctional groups typically relies on ethylenic unsaturation, preferablyterminal ethylenic unsaturation, present in the copolymer for reactionwith a functional compound containing or constituting the functionalgroup. Thus, reaction of these functional compounds and the copolymercan occur through a variety of mechanisms. Useful and preferredfunctional groups include halogen, carboxyl materials present as acids,esters, salts, or anhydrides, alcohols, amines, ketones, aldehydes andthe like.

Useful functionalization reactions which are generally well known tothose skilled in the art include the following. However, the uniquefeatures of the POH copolymers of the present invention providesignificant advantages not previously available:

(A) reaction of the copolymer at its point of unsaturation with carbonmonoxide using a Koch-type reaction wherein an acid group such as an isoacid or neo acid is formed. Functionalization of POH copolymers by meansof the Koch reaction and production of derivatives therefrom can becarried out according to the general teachings in WO/94/13709, publishedJun. 23, 1994 (incorporated herein for the purposes of U.S.prosecution). However, use of the Koch reaction with ethylene/α-olefincopolymers and α-olefin homopolymers containing primarily vinylideneand/or trisubstituted double bonds (e.g., produced by means ofmetallocene catalyst systems from ethylene and α-olefin feed streams)leads to derivatives containing more than 50% neoacid derivatives. Thesteric hindrance about the α-carbon of such neoacid derivatives makessuch materials more difficult to condense with polyamines to formdispersants. High temperatures and aryl leaving groups are required inorder to drive the reaction to completion. The POH copolymer of thepresent invention which contains a significant concentration of vinyland/or vinylene terminated copolymer chains results in significantlymore isoacid structures which are easier to derivatize and thereforemore desirable. In particular, the chemically modified POH copolymers ofthe present invention typically contain less than 50% of neo-substitutedcarbonyl groups, preferably less than 40%, more preferably less than 30%and most preferably less than 20% neo-substituted carbonyl groups. Forexample, the modified POH copolymers of the present invention typicallywill contain from about 5 to less than about 50% neo-substitutedcarbonyl groups; preferably from about 5 to about 40%; more preferablyfrom about 5 to about 30%; most preferably from about 5 to about 25% ofsuch groups;

(B) hydroformylation or oxycarbonylation with cobalt or rhodiumcatalysts introduce a carbonyl group at the less hindered end of atrisubstituted double bond, leading to isoaldehydes and acids (see,WO/95/24431, published Sep. 14, 1995; incorporated herein by referencefor the purposes of U.S. prosecution); amine derivatives useful asderivatives can be formed by either a single step aminomethylationprocess or a two step hydroformylation and reductive amination process.However, vinyl olefins which are present at higher concentrations in thePOH copolymers of this invention, lead to the completely unhinderedprimary functional group which is easiest to derivatize. Consequently,the presence of vinyl olefins enables the condensation of the polymericacid with polyamines directly without the necessity of phenols asleaving groups;

(C) acyl functionalization, and in particular, the preferred maleationreaction, which is the reaction of the copolymer at the point ofunsaturation with maleic acid or anhydride. A related reaction is thealternating copolymerization of maleic anhydride with copolymerscontaining vinylidene unsaturation, but the degree of polymerization insuch systems is limited, e.g., from about 5-10. In contrast, the vinylgroups of the POH copolymers of the present invention are much moreamenable to radical initiated copolymerization leading to asignificantly higher degree of polymerization (DP), e.g., a DP greaterthan about 20. The functionalized reaction product can be furtherreacted with, e.g., amines to produce dispersant products. When thereactant is a polyamine, polyol or aminoalcohol, the reaction isconducted in the presence of sufficient chain-stopping or end-cappingco-reactant to ensure a gel-free product (see WO94/13761, published Jun.23, 1994, incorporated herein by reference for the purposes of U.S.prosecution). Alternatively, functionalization can be accomplished byreaction of the copolymer with an unsaturated functional compound usingthe “ene” reaction absent halogenation;

(D) halogenation of the copolymer at the olefinic bond and subsequentreaction of the halogenated copolymer with an ethylenically unsaturatedfunctional compound or an amine;

(E) reaction of the copolymer with the functional compound by freeradical addition using a free radical catalyst; and

(F) reaction of the copolymer by air oxidation methods, epoxidation,chloroamination or ozonolysis.

(G) reaction of the copolymer with at least one phenol group thuspermitting derivatization in a Mannich Base-type condensation (see, forexample, U.S. Pat. No. 5,128,056 issued Jul. 7, 1992 and U.S. Pat. No.5,200,103 issued Apr. 6, 1993, each incorporated herein by reference forpurposes of U.S. prosecution).

Characterization of the degree to which the copolymer has beenfunctionalized is referred to herein as “functionality”. Functionalityrefers generally to the average number of functional groups presentwithin the copolymer structure per copolymer chain. Thus, functionalitycan be expressed as the average number of moles of functional groups per“mole of copolymer”. When said “mole of copolymer” in the functionalityratio includes both functionalized and unfunctionalized copolymer,functionality is referred to herein as F. When said “mole of copolymer”includes only functionalized copolymer, functionality is referred toherein as F*. Typical analytical techniques employed to determine F*will normally necessitate identification of the weight fraction offunctionalized copolymer, based on the total weight of copolymer(functionalized+unfunctionalized) in the sample being analyzed forfunctionality. This weight fraction is commonly referred to as ActiveIngredient or A.I. Since the determination of A.I. is a separateanalytical step, it can be more convenient to express functionality as Frather than F*. In any event, both F and F* are alternate ways ofcharacterizing the functionality.

The particular functionality selected, for copolymer intended to bederivatized, will depend on the nature of the derivatization reactionsand type and number of chemical linkages established by the derivatizingcompound. In most instances, one derivatizing linkage will be formed foreach functional group, e.g., each carboxy functional group will form oneester or amide linkage.

Accordingly, while any effective functionality can be imparted to thefunctionalized copolymer intended for subsequent derivatization, it iscontemplated that such functionalities, expressed as F*, can be, fordispersant end uses, typically not greater than 3, preferably notgreater than 2, and typically can range from 1 to 3, preferably from 1.5to 2.5, and most preferably from 1.1 to 2 (e.g. 1.2 to 1.3). F and F*values can be related using the A.I., which for copolymers of thepresent invention typically are at least 0.50, preferably from 0.65 to0.99, more preferably from 0.75 to 0.99, yet more preferably 0.85 to0.99. However, the upper limit of A.I. is typically from 0.90 to 0.99,and more typically 0.90 to 0.95. Where A.I. is 1.0, F=F*.

As indicated above, a functionalized copolymer is one which ischemically modified primarily to enhance its ability to participate in awider variety of chemical reactions than would otherwise be possiblewith the unfunctionalized copolymer. In contrast, a derivatizedcopolymer is one which has been chemically modified to perform one ormore functions in a significantly improved way relative to theunfunctionalized copolymer and/or the functionalized copolymer.Representative of such functions, are dispersancy and/or viscositymodification in lubricating oil compositions. Typically, derivatizationis achieved by chemical modification of the functionalized copolymer byreaction with at least one derivatizing compound to form derivatizedcopolymers. The derivatizing compound typically contains at least onereactive derivatizing group capable of reacting with the functionalgroups of the functionalized copolymers, for example, by nucleophilicsubstitution, Mannich Base condensation, transesterification, saltformations, and the like. The derivatizing compound preferably alsocontains at least one additional group suitable for imparting thedesired properties to the derivatized copolymer, e.g., polar groups.Thus, such derivatizing compounds typically will contain one or moregroups including amine, hydroxy, ester, amide, imide, thio, thioamido,oxazoline or salt groups derived from reactive metal or reactive metalcompounds. Thus, the derivatized copolymers can include the reactionproduct of the above recited functionalized copolymer with anucleophilic reactant, which includes, amines, alcohols, amino-alcoholsand mixtures thereof, to farm oil soluble salts, amides, imides,oxazoline, reactive metal compounds and esters of mono- and dicarboxylicacids, esters or anhydrides. Suitable properties sought to be impartedto the derivatized copolymer include especially dispersancy, but alsomultifunctional viscosity modification, antioxidancy, frictionmodification, antiwear, antirust, seal swell, and the like.

Ash-producing detergents can be made using the functionalized copolymersof the present invention as exemplified by oil-soluble neutral and basicsalts of alkali or alkaline earth metals with alkyl phenols, alkylsulfonic acids, carboxylic acids, salicylic acids or organic phosphorusacids characterized by at least one direct carbon-to-phosphorus linkagesuch as those prepared from the functionalized olefin copolymer of thepresent invention (e.g., functionalized copolymer having a molecularweight of 1,500) with a phosphorizing agent such as phosphorustrichloride, phosphorus heptasulfide, phosphorus pentasulfide,phosphorus trichloride and sulfur, white phosphorus and a sulfur halide,or phosphorothioic chloride. The most commonly used salts of such acidsare those of sodium, potassium, lithium, calcium, magnesium, strontiumand barium. The alkyl groups of the above acids or compounds constitutethe copolymer of the present invention. Preferred ash-producingdetergents which can be derived from the functionalized copolymers ofthe present invention include the metal salts of alkyl sulfonic acids,alkyl phenols, sulfurized alkyl phenols, alkyl salicylates, alkylnaphthenates and other oil soluble mono- and dicarboxylic acids. Highlybasic (viz., overbased) metal salts, such as highly basic alkaline earthmetal alkyl sulfonates (especially Ca and Mg salts) are frequently usedas detergents.

The derivatized copolymer compositions of the present invention can beused as ashless dispersants in lubricant and fuel compositions. Ashlessdispersants are referred to as being ashless despite the fact that,depending on their constitution, the dispersants may, upon combustion,yield a non-volatile material such as boric oxide or phosphoruspentoxide. The compounds useful as ashless dispersants generally arecharacterized by a “polar” group attached to a relatively high molecularweight hydrocarbon chain supplied by the copolymer of the presentinvention. The “polar” group generally contains one or more of theelements nitrogen, oxygen and phosphorus. The solubilizing chains aregenerally higher in molecular weight than those employed with themetallic based dispersants, but in some instances they may be quitesimilar. Various types of ashless dispersants can be made byderivatizing the copolymer of the present invention and are suitable foruse in the lubricant compositions. The following are illustrative (wherereference is made to relevant patents, it is to be understood that thecited patents are incorporated herein for the purposes of U.S.prosecution):

1. Reaction products of functionalized copolymer of the presentinvention derivatized with nucleophilic reagents such as aminecompounds, e.g. nitrogen-containing compounds, organic hydroxy compoundssuch as phenols and alcohols, and/or basic inorganic materials. Morespecifically, nitrogen- or ester-containing ashless dispersants comprisemembers selected from the group consisting of oil-soluble salts, amides,imides, oxazolines and esters, or mixtures thereof, of the copolymer ofthe present invention, functionalized with mono- and dicarboxylic acidsor anhydride or ester derivatives thereof, said copolymer havingdispersant range molecular weights as defined hereinabove. At least onefunctionalized copolymer is mixed with at least one of amine, alcohol,including polyol, aminoalcohol, etc., to form the dispersant additives.One class of particularly preferred dispersants includes those derivedfrom the copolymer of the present invention functionalized mono- ordicarboxylic acid material, e.g. succinic anhydride, and reacted with(i) a hydroxy compound, e.g. pentaerythritol, (ii) a polyoxyalkylenepolyamine, e.g. polyoxypropylene diamine, and/or (iii) a polyalkylenepolyamine, e.g., polyethylene diamine, tetraethylene pentamine (“TEPA”)or triethylene tetramine (“TETA”). Another preferred dispersant classincludes those derived from functionalized copolymer reacted with (i) apolyalkylene polyamine, e.g. tetraethylene pentamine, and/or (ii) apolyhydric alcohol or polyhydroxy-substituted aliphatic primary amine,e.g., pentaerythritol or trismethylolamino methane.

Further enhancements in dispersancy can be achieved by the use ofmaterials known as heavy polyalkylene polyamines (“heavy PAM”) tointroduce an amine as the polar segment of the dispersant (see, e.g.,U.S. Ser. No. 322715 filed Oct. 12, 1994; incorporated herein byreference for the purposes of U.S. prosecution). Generally, heavy PAM isa mixture of higher oligomers of polyalkylene amines (e.g.,polyethylene) containing essentially no TEPA, at most small amounts ofpentaethylene hexamine (“PEHA”), but primarily oligomers with more than6 nitrogens and more branching than conventional polyamine mixtures.Specifically, heavy PAM typically contains >28% nitrogen (e.g., >32%),an equivalent weight of primary amine groups of between 120-160 gramsper equivalent (e.g., 125-140), more than 6 nitrogen atoms per moleculeon the average and more than two primary amines per molecule on theaverage and essentially no oxygen. Heavy PAM is available commercially(e.g., trade name Polyamine HA-2, Dow Chemical Company) and can also besynthesized from polyethylene or polypropylene polyamine. Reduced levelsof free, unreacted polyamine is beneficial to diesel engine andelastomer seal performance in vehicles.

2. Reaction products of the copolymer of the present inventionfunctionalized with an aromatic hydroxy group and derivatized withaldehydes (especially formaldehyde) and amines (especially polyalkylenepolyamines), through the Mannich reaction, which may be characterized as“Mannich dispersants”.

3. Reaction products of the copolymer of the present invention whichhave been functionalized by reaction with halogen and then derivatizedby reaction with amines (e.g. direct amination), preferably polyalkylenepolyamines. These may be characterized as “amine dispersants” andexamples thereof are described, for example, in U.S. Pat. Nos.3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,755,433; 3,822,209 and5,084,197.

Useful amine compounds for derivatizing functionalized copolymerscomprise at least one amine and can comprise one or more additionalamines or other reactive or polar groups. Where the functional group isa carboxylic acid, ester or derivative thereof, it reacts with the amineto form an amide. Where the functional group is an epoxy it reacts withthe amine to form an amino alcohol. Where the functional group is ahalide the amine reacts to displace the halide. Where the functionalgroup is a carbonyl group it reacts with the amine to form an imine.Amine compounds useful as nucleophilic reactants for reaction with thefunctionalized copolymer of the present invention include thosedisclosed in U.S. Pat. Nos. 3,445,441, 5,017,299 and 5,102,566.Preferred amine compounds include mono- and (preferably) polyamines, of2 to 60, preferably 2 to 40 (e.g. 3 to 20), total carbon atoms of 1 to12, preferably 3 to 12, and most preferably 3 to 9 nitrogen atoms in themolecule. These amines may be hydrocarbyl amines or may be hydrocarbylamines including other groups, e.g., hydroxy groups, alkoxy groups,amide groups, nitriles, imidazoline groups, and the like. Hydroxy amineswith 1 to 6 hydroxy groups, preferably 1 to 3 hydroxy groups, areparticularly useful. Preferred amines are aliphatic saturated amines.

The functionalized copolymers, particularly acid functionalizedcopolymers, of the present invention can be reacted with alcohols, e.g.to form esters. The alcohols may be aliphatic compounds such asmonohydric and polyhydric alcohols or aromatic compounds such as phenolsand naphthols. The esters may be prepared, for example, by reacting asuitable alcohol or phenol with the acid or anhydride (i.e.,functionalized copolymer succinic anhydride). Ester derivatives likewisemay be obtained by the reaction of a acid functionalized copolymer withepoxide or a mixture of an epoxide and water. Such reaction is similarto one involving the acid or anhydride with a glycol. For instance, theproduct may be prepared by the reaction of functionalized copolymer withalkylene oxide to yield half-esters, monoesters or diesters. In lieu ofthe acid functionalized copolymer, a copolymer functionalized withlactone acid or an acid halide may be used in the processes illustratedabove for preparing the ester derivatives of this invention. Such acidhalides may be acid dibromides, acid dichlorides, acid monochlorides,and acid monobromides. The derivative compositions produced by reactingfunctionalized copolymer with alcohols are esters including both acidicesters and neutral esters. Acidic esters are those in which less thanall of the functional groups in functionalized copolymer are esterified,and hence possess at least one free functional group. Obviously, acidesters are easily prepared by using an amount of alcohol insufficient toesterify all of the functional groups in the functionalized copolymer.

Procedures are well known for reacting high molecular weight carboxylicacids with alcohols to produce acidic esters and neutral esters. Thesesame techniques are applicable to preparing esters from thefunctionalized copolymer of this invention and the alcohols describedabove. All that is required is that the functionalized copolymers ofthis invention be substituted for the high molecular weight carboxylicacids discussed in these patents, usually on an equivalent weight basis.The following U.S. patents disclose suitable methods for reacting thefunctionalized copolymers of this invention with the alcohols describedabove: U.S. Pat. Nos. 3,331,776; 3,381,022; 3,522,179; 3,542,680;3,697,428 and 3,755,169.

The hydroxy aromatic functionalized copolymer aldehyde/amino condensatesuseful as ashless dispersants in the compositions of this inventioninclude those generally referred to as Mannich condensates. Generallythey are made by reacting simultaneously or sequentially at least oneactive hydrogen compound such as a hydrocarbon-substituted phenol (e.g.,hydroxy aromatic functionalized copolymer of the present invention),having at least one hydrogen atom bonded to an aromatic carbon, with atleast one aldehyde or aldehyde-producing material (typicallyformaldehyde precursor) and at least one amino or polyamino compoundhaving at least one NH group. Preferred phenolic compounds include thehydroxy aromatic functionalized copolymer and useful amine compounds arewell known and referred to above. The amine compounds include primary orsecondary monoamines having hydrocarbon substituents of 1 to 30 carbonatoms or hydroxyl-substituted hydrocarbon substituents of 1 to about 30carbon atoms. Another type of typical amine compound are the polyamines.The materials described in the following patents are illustrative ofMannich dispersants: U.S. Pat. Nos. 3,413,347; 3,697,574; 3,725,277;3,725,480; 3,726,882; 4,454,059 and 5,102,566.

A useful group of Mannich Base ashless dispersants are those formed bycondensing phenol functionalized copolymer with formaldehyde andpolyethylene amines, e.g., tetraethylene pentamine, pentaethylenehexamine, polyoxyethylene and polyoxypropylene amines, e.g.,polyoxypropylene diamine and combinations thereof. One particularlypreferred dispersant comprises a condensation of (A) phenolfunctionalized copolymer, (B) formaldehyde, (C) a polyoxyalkylenepolyamine, e.g., polyoxypropylene diamine, and (D) a polyalkylenepolyamine, e.g. polyethylene diamine and tetraethylene pentamine, usingabout 2 to about 8 moles each of (B) and about 1 to about 4 moles of (C)or (D) per mole of (A).

A useful class of nitrogen-containing condensation products for use inthe present invention are those made by a “2-step process” as disclosedin U.S. Pat. No. 4,273,891. Briefly, these nitrogen-containingcondensates are made by (1) reacting at least phenol functionalizedcopolymer of the present invention with a lower aliphatic C₁ to C₇aldehyde or reversible copolymer thereof in the presence of an alkalinereagent, such as an alkali metal hydroxide, at a temperature up to about150° C.; (2) substantially neutralizing the intermediate reactionmixture thus formed; and (3) reacting the neutralized intermediate withat least one compound which contains an amino group having at least one—NH— group. These 2-step condensates can be made from (a) phenolfunctionalized copolymer and (b) formaldehyde, or reversible copolymerthereof, (e.g., trioxane, paraformaldehyde) or functional equivalentthereof, (e.g., methylol) and (c) an alkylene polyamine such as ethylenepolyamines having between 2 and 10 nitrogen atoms.

Condensates made from sulfur-containing reactants also can be used inthe compositions of the present invention. Such sulfur-containingcondensates are described in U.S. Pat. Nos. 3,368,972; 3,649,229;3,600,372; 3,649,659 and 3,741,896. These patents also disclosesulfur-containing Mannich condensates.

4. Useful reactive metals or reactive metal compounds are those whichwill form metal salts or metal-containing complexes with thefunctionalized copolymer. Metal complexes are typically achieved byreacting the functionalized copolymers with amines and/or alcohols asdiscussed above and also with complex forming reactants either during orsubsequent to amination. Reactive metal compounds for use in theformation of complexes with the reaction products of functionalizedcopolymer and amines include those disclosed in U.S. Pat. No. 3,306,908.Complex-forming metal reactants include the nitrates, nitrites, halides,carboxylates, phosphates, phosphites, sulfates, sulfites, carbonates,borates, and oxides of cadmium as well as metals having atomic numbersfrom 24 to 30 (including chromium, manganese, iron, cobalt, nickel,copper and zinc). These metals are the so-called transition orcoordination metals, i.e., they are capable of forming complexes bymeans of their secondary or coordination valence.

Processes are disclosed in U.S. Pat. No. 3,306,908 and Re. 26,433 whichare applicable to the carboxylic derivative compositions of thefunctionalized copolymer of this invention with the amines as describedabove by substituting, on an equivalent basis, the functionalizedcopolymer of this invention with the high molecular weight carboxylicacid functionalized polymer of U.S. Pat. No. 3,306,908 and carboxylicacylating agents of Re. 26,433. Similarly, the metal salts of U.S. Pat.No. 3,271,310 can be adapted to make the present functionalizedcopolymer.

Lubricant and Fuel-Oil Applications

The copolymer of this invention, having a suitable number averagemolecular weight, may be used as a synthetic base oil. Thefunctionalized copolymer, in addition to acting as intermediates fordispersant manufacture, can be used as a molding release agent, moldingagent, metal working lubricant, point thickener and the like. Theprimary utility for the above-described materials, from copolymer allthe way through and including post-treated derivatized copolymer, is asan additive for oleaginous compositions. For ease of discussion, theabove-mentioned materials are collectively and individually referred toherein as additives when used in the context of an oleaginouscomposition containing such “additives”. Accordingly, the additives ofthe present invention may be used by incorporation and dissolution intoan oleaginous material such as fuels and lubricating oils. When theadditives of this invention are used in normally liquid petroleum fuelssuch as middle distillates boiling from 65° C. to 430° C., includingkerosene, diesel fuels, home heating fuel oil, jet fuels, etc., there istypically used a concentration of the additives in the fuel in the rangeof from 0.001 to 0.5, and preferably 0.005 to 0.15 wt. %, based on thetotal weight of the composition. Useful compositions and additives aredisclosed in U.S. Pat. No. 5,102,566.

The additives of the present invention, particularly those adapted foruse as dispersants, can be incorporated into a lubricating oil in anyconvenient way. Thus, they can be blended with other additives prior toblending with the oil or added directly to the oil by dispersing ordissolving the same in the oil at the desired level or concentration ofthe additive; such blending steps can be conducted at room temperatureor elevated temperatures. Alternatively, the additives can be blendedwith a suitable oil-soluble solvent and base oil to form a concentrate,and then blending the concentrate with a lubricating oil basestock toobtain the final formulation. Such dispersant concentrates willtypically contain (on an active ingredient (A.I.) basis) from 10 to 80wt. %, typically 20 to 60 wt. %, and preferably from 40 to 50 wt. %,additive, and typically from 40 to 80 wt. %, preferably from 40 to 60wt. %, base oil, i.e., hydrocarbon oil based on the concentrate weight.The lubricating oil basestock for the additive typically is adapted toperform a selected function by the incorporation of additional additivestherein to form lubricating oil compositions (i.e., formulations).Usually concentrates may be diluted with 3 to 100, e.g., 5 to 40 partsby weight of lubricating oil, per part by weight of the additivepackage, in forming finished lubricants, e.g. crankcase motor oils. Thepurpose of concentrates, of course, is to make the handling of thevarious materials less difficult and awkward as well as to facilitatesolution or dispersion in the final blend. Thus, the additives of thepresent invention and formulations containing them would usually beemployed in the form of a 40 to 50 wt. % concentrate, for example, in alubricating oil fraction.

The additives of the present invention are primarily useful inlubricating oil compositions which employ a base oil in which theadditives are dissolved or dispersed therein. Such base oils may benatural or synthetic. Natural base oils include mineral lubricating oilswhich may vary widely as to their crude source, e.g., whetherparaffinic, naphthenic, mixed paraffinic-naphthenic, and the like; aswell as to their formation, e.g., distillation range, straight run orcracked, hydrofined, solvent extracted and the like. Base oils suitablefor use in preparing the lubricating oil compositions of the presentinvention include those conventionally employed as crankcase lubricatingoils for spark-ignited and compression-ignited internal combustionengines, such as automobile and truck engines, marine and railroaddiesel engines, and the like. Advantageous results are also achieved byemploying the additive mixtures of the present invention in base oilsconventionally employed in and/or adapted for use as power transmittingfluids, universal tractor fluids and hydraulic fluids, heavy dutyhydraulic fluids, power steering fluids and the like. Gear lubricants,industrial oils, pump oils and other lubricating oil compositions canalso benefit from the incorporation therein of the additives of thepresent invention. The additives of the present invention will begenerally used in admixture with a lube oil basestock, comprising an oilof lubricating viscosity, including natural and synthetic lubricatingoils and mixtures thereof. Useful oils are described in U.S. Pat. Nos.5,017,299 and 5,084,197. Natural oils include animal oils and vegetableoils (e.g., castor, lard oil) liquid petroleum oils and hydrorefined,solvent-treated or acid-treated mineral lubricating oils of theparaffinic, naphthenic and mixed paraffinic-naphthenic types.Lubricating oils useful in the present invention are typically based ona hydrocarbon mineral oil having a viscosity of about 2-40 centistokes(ASTM D-445) at 100° C. Oils of lubricating viscosity derived from coalor shale are also useful base oils. Lubricating oil basestocks comprisedof a mixture of a hydrocarbon mineral oil and up to about 50 weight % ofa synthetic lubricating oil are also considered suitable. Syntheticlubricating oils include hydrocarbon oils and halosubstitutedhydrocarbon oils such as polymerized and interpolymerized olefins,esters of dibasic acids and complex esters derived from monobasic acidsand complex esters derived from monobasic acids, polyglycols, dibasicacids and alcohols. Alkylene oxide copolymers and interpolymers andderivatives thereof where the terminal hydroxyl groups have beenmodified by esterification, etherification, etc., constitute anotherclass of known synthetic lubricating oils. Other suitable classes ofsynthetic lubricating oils comprise the esters of dicarboxylic acids andsilicon and silicate based oils. Additionally, unrefined, refined andrerefined oils can be used in the lubricants of the present invention.

The POH copolymers of the present invention are useful in oilcompositions, for example fuel oil compositions, and particularly infuel oil compositions susceptible to wax formation at low temperatures.Heating oils and other distillate petroleum fuels, for example, dieselfuels, contain alkanes that at low temperatures tend to precipitate aslarge crystals of wax in such a way as to form a gel structure whichcauses the fuel to lose its ability to flow. The lowest temperature atwhich the fuel will flow is known as the pour point.

As the temperature of the fuel falls and approaches the pour point,difficulties arise in transporting the fuel through lines and pumps.Further, the wax crystals tend to plug fuel lines, screens and filtersat temperatures above the pour point. These problems are recognized inthe art and various additives have been proposed, many of which are incommercial use, for depressing the pour point of fuel oils. Similarly,other additives have been proposed and are in commercial use forreducing the size and changing the shape of wax crystals that do form.Smaller size crystals are desirable since they are less likely to clog afilter; certain additives inhibit the was from crystallizing asplatelets and cause it to adopt an acicular habit, the resulting needlesbeing more likely to pass through a filter than are platelets. Theadditives may also have the effect of retaining in suspension in thefuel the crystals that have formed, the resulting reduced settling alsoassisting in prevention of blockages.

Preferred POH copolymers of the invention may be further characterizedby their beneficial effect on pour point, as determined by ASTM MethodNo. D97. In this test, measurements are made on solutions comprising aspecific concentration of the copolymer of the invention in a standardmineral lubricating oil (S150N). The pour point of an oil composition isthe lowest temperature at which it will flow when chilled in a specificmanner; here, the manner prescribed by ASTM Method No. D97; pour pointcharacterizes the low temperature flow or pumpability properties offluids such as lubricating and fuel oils. Useful additives can also beproduced from the POH copolymers of the invention for use in variousmiddle distillate fuel compositions for lowering the pour point andcontrolling the size of wax crystals in these products; such additivesare known as wax crystal modifiers (WCM). The copolymers of the presentinvention are also useful as “coadditives” with another WCM of thepresent invention or in combination with prior art WCM additives. Sincecertain wax crystal modifiers are capable of affecting the size andnumber of wax crystals (e.g., affecting crystal nucleation processes)and others are capable of affecting the shape of such crystals (e.g.,affecting crystal growth processes), preferred performance may beachieved by the judicious combination of WCM additives that areeffective in these different respects; each having somewhat differentstructural characteristics to accomplish their result. For example,copolymers of the invention useful for the purpose of affectingnucleation can have fewer than about 10 branches per 100 carbon atoms;useful copolymers can have fewer than 6 branches, e.g., about 5 branchesper 100 carbon atoms.

The general term “lubricating oil flow improver” (LOFI) is also used toidentify those additives which modify the size, number and growth rateof wax crystals in lube oils in such a way as to impart improved lowtemperature handling, pumpability and/or vehicle operability. Copolymersor additives containing copolymers, which can also be in variousfunctionalized or derivatized forms, are used for this purpose. In onetype of LOFI, the copolymer backbone methylene sequences which arerandomly distributed are interrupted by branches (and othercon-crystallizable segments). It is the sequences that are believed toassociate or co-crystallize with the wax crystals and the branches whichinhibit or interfere with further crystal growth that would ordinarilyoccur in their absence. Where the branches are methylene side chains ofincreased length, such side chains can be particularly effective intreating lube oils containing isoparaffins and n-paraffins. Theeffectiveness of an additive bears a complex relationship to copolymerstructure and is not readily predictable.

A requirement of any dispersant additive is that it not adversely affect(i.e., does not significantly increase) the pour point of thelubricating oil composition to which it is added. It is generallyaccepted that the pour point behavior of dispersant additives is largelydetermined by the pour point behavior of the copolymer from which theyare derived. More particularly, the addition to a lubricating oilcomposition of an effective amount of a dispersant additive produced bythe functionalization and/or derivatization, as hereinafter described,of the POH copolymer does not negatively alter the pour point of thecomposition in a significant way.

The POH copolymers of this invention are also capable of functioning asa wax crystal modifier (WCM) in fuel oil compositions. In thisapplication, performance can be measured by a pour point test, thechange in pour point, measured in degrees Centigrade, when an effectiveamount of the WCM is present in the fuel oil. Performance can also bemeasured by a filterability test, e.g., the cold filter plugging point(“CFPP”) test, which is known to those skilled in the art. The extent ofmodification of the wax crystal and the effectiveness of the WCM willvary depending on the structural configuration of the WCM. This, inturn, is affected by the monomer used for polymerization, e.g., whethera C₈ or a C₁₄ is used, or a mixture of monomers. Furthermore, the extentof partial “chain straightening” effected by the particular catalystemployed (as explained elsewhere), will vary the performance of the POHcopolymer as a wax crystal modifier. Selection of monomer, catalyst andpolymerization conditions can be made in order to maximize performanceof the resulting POH copolymer in this application.

Among other factors affecting pour point and/or CFPP performance,besides the extent of branching, are the apparent ethylene content andthe number average molecular weight of the copolymer. Since highercopolymer molecular weight generally increases the viscosity of the oilin which it is dissolved, the choice of copolymer molecular weightshould be made with consideration of how it will affect the flowproperties of the resulting composition. Similarly, higher levels ofapparent ethylene sequences results in the potential for greaterparticipation in the crystallization process and solubility in the oil.The extent and nature of branching can serve as a fine tuning variableto “balance” the extent of crystallinity of the WCM itself so that itremains soluble in the oil and still functions to interact with the waxas required.

Lubricating oil formulations containing the additives of the presentinvention conventionally contain other types of additives thatcontribute other characteristics that are required in the formulation.Typical of such other additives are detergent/inhibitors, viscositymodifiers, wear inhibitors, oxidation inhibitors, corrosion inhibitors,friction modifiers, foam inhibitors, rust inhibitors, demulsifiers, lubeoil flow improvers, and seal swell control agents, etc. Some of theadditives can provide multiple effects e.g., a dispersant oxidationinhibitor. Compositions, when containing these additives, typically areblended into the base oil in amounts which are effective to providetheir normal attendant function. Representative effective amounts ofsuch additives are illustrated as follows:

Range Broad Preferred Compositions Wt % Wt % Viscosity Index Improver 1-12 1-4 Corrosion Inhibitor 0.01-3   0.01-1.5  Oxidation Inhibitor0.01-5   0.01-1.5  Dispersant 0.1-10  0.1-5   Lube Oil Flow Improver0.01-2   0.01-1.5  Detergents and Rust 0.01-6   0.01-3   Inhibitors PourPoint Depressant 0.01-1.5  0.01-1.5  Anti-Foaming Agents 0.001-0.1 0.001-0.01  Antiwear Agents 0.001-5    0.001-1.5  Seal Swellant 0.1-8  0.1-4   Friction Modifiers 0.01-3   0.01-1.5  Lubricating Base OilBalance Balance

When the copolymers of this invention are employed in lubricating oilsas viscosity index (VI) improvers or viscosity modifiers theirconcentration can vary broadly from about 0.001 to 49 wt. %. Theproportions giving the preferred results will vary somewhat according tothe nature of the lubricating oil basestock and the specific purpose forwhich the lubricant is to serve in a particular application. When usedas lubricating oils for diesel or gasoline engine crankcase lubricants,the copolymer concentrations are within the range of about 0.1 to 15.0wt. % of the total composition which are amounts effective to provideviscosity modification and/or VI improvement.

When other additives are employed, it may be desirable, although notnecessary, to prepare additive concentrates comprising concentratedsolutions or dispersions of the subject additives of this invention (inconcentrate amounts hereinabove described), together with one or more ofsaid other additives (said concentrate when constituting an additivemixture being referred to herein as an additive-package) whereby severaladditives can be added simultaneously to the base oil to form thelubricating oil composition. Dissolution of the additive concentrateinto the lubricating oil may be facilitated by solvents and by mixingaccompanied with mild heating, but this is not essential. Theconcentrate or additive-package will typically be formulated to containthe additives in proper amounts to provide the desired concentration inthe final formulation when the additive-package is combined with apredetermined amount of base lubricant. Thus, the subject additives ofthe present invention can be added to small amounts of base oil or othercompatible solvents along with other desirable additives to formadditive-packages containing active ingredients in collective amounts oftypically from 2.5 to 90%, and preferably from 15 to 75%, and mostpreferably from 25 to 60% by weight additives in the appropriateproportions with the remainder being base oil. The final formulationsmay employ typically 10 wt. % of the additive-package with the remainderbeing base oil. (All weight percents expressed herein, unless otherwiseindicated, are based on active ingredient (A.I.) content of theadditive, and/or upon the total weight of any additive-package, orformulation which will be the sum of the A.I. weight of each additiveplus the weight of total oil or diluent).

EXAMPLES

The following examples are given as illustrations of the claimedinvention. It should be understood, however, that the invention is notlimited to the specific details set forth in the examples. All parts andpercentages in the examples are by weight unless otherwise specified.

Example 1

Ethylene (E), propylene (P) or butene-1 (B) is copolymerized with methylacrylate (MA), tert-butyl acrylate (tBuA) or methyl vinyl ketone (MVK)at ambient pressure or elevated pressure, as described below. Thecatalyst system is prepared according to the disclosure in J.Am.ChemSoc.1996, 118, 267-268 (including supporting information); the catalyststructure is shown in A, below. Comonomer concentration (moles) isvaried from 0.5 to 6.0.

Ambient pressure polymerization: A Schlenk flask containing the catalystprecursor is cooled to −78° C., evacuated, and placed under the α-olefinatmosphere (e.g., ethylene, propylene or butene-1). Methylene chlorideand the acrylate are added to the cold flask via syringe. The solutionis allowed to warm to room temperature with stirring. Followingpolymerization for the desired reaction time, the reaction mixture isadded to approx. 600 mL or methanol to precipitate the polymer. Themethanol is decanted and the polymer is dissolved in approx. 600 mL ofEt₂O or petroleum ether. The solution is filtered through a plug ofcelite and/or neutral alumina, the solvent is removed and the polymer isdried in vacuo for several days. The copolymers are isolated as viscousoils.

Elevated pressure polymerization: A mechanically stirred, 300 mL Parr®reactor is used which is equipped with an electric heating mantlecontrolled by a thermocouple dipping into the reaction mixture. Asolution of 0.1 mmol of catalyst precursor in methylene chloride,containing the comonomer (5-50 mL, total volume of the liquid phase: 100mL), is transferred via cannula to the reactor under a nitrogenatmosphere. After repeatedly flushing with ethylene or propylene,constant pressure is applied by continuously feeding the gaseous olefinand the contents of the reactor are vigorously stirred. Afterpolymerization, the gas is vented. Volatiles are removed from thereaction mixture in vacuo, and the polymer is dried under vacuumovernight. Residual comonomer is removed by precipitating the polymerfrom methylene chloride solution with methanol.

Catalyst structure A:

Several polymerization runs are made under the following conditions toprepare the POH copolymers of the present invention:

Run Monomers Pressure 1 E/MA Elevated 2 E/tBuA Ambient 3 P/MA Elevated 4B/MA Ambient 5 B/MVK Elevated

The copolymers are amorphous, terminally unsaturated, highly branchedolefin-acrylate copolymers having a relatively narrow molecular weightdistribution with the acrylate moiety present predominantly at the endof the branches.

Example 2

Amination of the product of Example 1/Run 1 with a polyamine and a chainstopper (polyisobutenyl succinic anhydride).

200 gms of the modified polymer of Example 1/Run 4 are placed in asuitable glass reactor equipped with adequate stirring. The reactor ispurged with nitrogen for 30 minutes and the contents are heated to about100° C. About 350 gms of polyisobutenyl succinic anhydride having anASTM, D-64 Sap. No. 112 which are diluted with 350 gms of solvent 100Ndiluent oil are added to the polymer with stirring and the temperatureis raised to about 190° C. The reaction mixture is held at thattemperature with nitrogen stripping for 3 hours, followed by cooling.The resulting product is a viscous liquid substantially free of gel.

Example 3

The copolymer of Example 1/Run 4 is aminated with a polypropylenetetraamine with one end substituted with a tallow group withapproximately one primary amine per molecule and a nitrogen content of12.4%. The reagents are mixed at room temperature and heated to 200° C.for 7 hrs. while nitrogen stripping. The reaction mixture showsconversion to the corresponding amide. About 150 g of the amide isdiluted in 99 g of S15N mineral oil and heated to 145° C. and 9.35 g ofa 30% boric acid slurry in oil is added over one hour. After addition iscomplete, the temperature is raised to 150° C. and the reaction mixtureis nitrogen stripped for one hour. The corresponding borated, aminateddispersant derivative is produced.

Example 4

the copolymer of Example 1/Run 4 is aminated with a polypropylene etherpentamine with only one end substituted with a dodecyl alkyl group withapproximately one primary amine group per molecule and a nitrogencontent of 12.92%. The reagents are mixed at room temperature and heatedto 220° C. for 4 hrs. The produce is stripped with nitrogen for 3 hrs.at 200° C. resulting in an amide derivative. About 1,540 g of the amideare diluted with 810 g of S150N and the oil solution borated at 145° C.with 105 g of a 30% boric acid slurry as previously described. Aborated, aminated dispersant derivative is produced.

Example 5

The POH copolymer of Example 1/Run 1 is aminated with2-ethylhexylaminopropylaminopropylaminopropylamine with approximatelyone primary amino group per molecule and a nitrogen content of 18.24% byheating to 200° C. The reaction mixture is vacuum heated (10-20 mm Hg)for several hours until the reaction shows conversion to the amide andthe amide is nitrogen stripped. The product is diluted in mineral oil tomake a 50% solution and borated using the process described in thepreceding examples to yield a borated, aminated dispersant derivative.

Example 6

235 g of the POH copolymer of Example 1/Run 4 is heated to 180° C. and23 g of dimethylaminopropylaminopropylamine (DMAPAPA) havingapproximately one primary amine group per molecule and a nitrogencontent of 25.4% is added. The reaction mixture is heated at 180° C. forseveral hours to convert the copolymer to the corresponding amide andthe product is nitrogen stripped at 180° C. for 4 hrs. to distill offthe unreacted amine.

Example 7

Polymerization according to Example 1/Run 4 is carried out except that acontinuous process is used with an olefinic feed obtained from arefinery Raffinate 2 source in combination with methyl acrylate polarcomonomer and polymerization conditions are controlled to produce apolar olefinic hydrocarbon copolymer useful as a dispersant backbone,with Mn of about 1,000.

Various aspects of the invention and their relationship to one anothercan be represented as follows:

1. Hydrocarbon copolymer derived from at least one polymerizable polarmonomer and at least one polymerizable olefinic monomer, said copolymersuitable for use as a fuel or lubricant additive, said copolymer havingthe following characteristics:

(a) an average ethylene sequence length, ESL, of from about 1.0 to lessthan about 3.0;

(b) an average of at least 5 branches per 100 carbon atoms of thecopolymer chains comprising said copolymer;

(c) at least about 50% of said branches being methyl and/or ethylbranches;

(d) substantially all of said incorporated polar monomer is present atthe terminal position of said branches;

(e) at least about 30% of said copolymer chains terminated with a vinylor vinylene group;

(f) a number average molecular weight, Mn, of from about 300 to about10,000; and

(g) substantial solubility in hydrocarbon and/or synthetic base oil.

2. The copolymer of aspect 1 wherein said ESL is from about 1.0 to about1.5.

3. The copolymer of aspect 2 having an average of from about 10 to about12.5 branches per 100 carbon atoms of said copolymer chains.

4. The copolymer of aspect 3 wherein at least about 95% of said branchesare methyl and/or ethyl branches.

5. The copolymer of aspect 4 wherein at least about 95% of saidcopolymer chains are terminated with a vinyl or vinylene group.

6. The copolymer of aspect 5 having a number average molecular weight,Mn, of from about 700 to about 2,500.

7. The copolymer of aspect 1 wherein the incorporated polar moietyderived from said polymerizable polar monomer which is incorporated insaid copolymer is present at an average concentration of from about onepolar moiety for each 5,000 Mn segment of polymer backbone, includingbranches, to about one polar moiety for each 1,000 Mn segment.

8. The copolymer of aspect 7 wherein said polar monomer is selected fromthe group consisting of methyl acrylate, ethyl acrylate, tert-butylacrylate, methyl methacrylate, methyl ethylacrylate, ethyl methacrylate,ethyl ethylacrylate and methyl vinyl ketone.

9. The copolymer of aspect 8 wherein said olefinic monomer is selectedfrom the group consisting of ethylene, propylene and butene-1.

10. A composition of matter suitable for use as a fuel or lubricantadditive consisting essentially of hydrocarbon copolymer derived from atleast one polymerizable polar monomer and at least one polymerizableolefinic monomer; said copolymer having at least two nitrogen atomsincorporated therein; said polar monomer selected from α, β unsaturatedcarbonyl compounds represented by the formula:

wherein X is hydrogen (H), NH₂, R_(y) or OR_(y); R_(x) is H or a C₁-C₅straight or branched alkyl group and R_(y) is H or a C₁ to C₂₀ straightor branched alkyl group; for short chain unsaturated ester monomers,R_(y) is preferably a C₁-C₅ alkyl group and for long chain monomers,preferably a C₁₀ to C₁₈ alkyl group; said olefinic monomer selected fromthe group consisting of ethylene, C₃-C₂₀ α-olefins and a mixture ofC₃-C₂₀ αolefins; said copolymer having the following characteristics:

(a) an average ethylene sequence length, ESL, of from about 1.0 to lessthan about 3.0;

(b) an average of at least 5 branches per 100 carbon atoms of thecopolymer chains comprising said copolymer;

(c) at least about 50% of said branches being methyl and/or ethylbranches;

(d) substantially all of said incorporated polar monomer is present atthe terminal position of said branches;

(e) at least about 30% of said copolymer chains terminated with a vinylor vinylene group;

(f) a number average molecular weight, Mn, of from about 300 to about10,000; and

(g) substantial solubility in hydrocarbon and/or synthetic base oil.

11. The composition of matter of aspect 10 wherein the incorporatedpolar moiety derived from said polymerizable polar monomer which isincorporated in said copolymer is present at an average concentration offrom about one polar moiety for each 5,000 Mn segment of polymerbackbone, including branches, to about one polar moiety for each 1,000Mn segment.

12. The composition of matter of aspect 11 wherein said polar monomer isselected from the group consisting of methyl acrylate, ethyl acrylate,tert-butyl acrylate, methyl methacrylate, methyl ethylacrylate, ethylmethacrylate, ethyl ethylacrylate, methyl vinyl ketone and acrylamide.

13. The composition of matter of aspect 12 wherein said olefinic monomeris selected from the group consisting of ethylene, propylene andbutene-1.

14. The composition of matter of aspect 10 wherein said mixture ofC₃-C₂₀ α-olefins is selected from the group consisting of C₃, C₄, and C₅refinery or steam cracker feedstreams and raffinate derivatives thereof.

15. The composition according to aspect 10 wherein said polymerizableolefinic monomer is ethylene, said branches in said copolymer, element(b), are present at an average of from about 5 to about 33 branches per100 carbon atoms and said terminal groups of (d) are vinyl and saidpolar monomer is an alkyl acrylate.

16. A process for continuously producing hydrocarbon copolymer derivedfrom at least one polymerizable polar monomer and at least onepolymerizable olefinic monomer; said copolymer suitable for use as afuel or lubricant additive; said copolymer having the followingcharacteristics:

(a) an average ethylene sequence length, ESL, of from about 1.0 to lessthan about 3.0;

(b) an average of at least 5 branches per 100 carbon atoms of thecopolymer chains comprising said copolymer;

(c) at least about 50% of said branches being methyl and/or ethylbranches;

(d) substantially all of said incorporated polar monomer is present atthe terminal position of said branches;

(e) at least about 30% of said copolymer chains terminated with a vinylor vinylene group;

(f) a number average molecular weight, Mn, of from about 300 to about10,000; and

(g) substantial solubility in hydrocarbon and/or synthetic base oil;

said copolymer derived from at least one polymerizable polar monomerselected from α, β unsaturated carbonyl compounds represented by theformula:

wherein X is hydrogen (H), NH₂, R_(y) or OR_(y); R_(x) is H or a C₁-C₅straight or branched alkyl group and R_(y) is H or a C₁ to C₂₀ straightor branched alkyl group; for short chain unsaturated ester monomers,R_(y) is preferably a C₁-C₅ alkyl group and for long chain monomers,preferably a C₁₀ to C₁₈ alkyl group; and at least one polymerizableolefinic monomer selected from the group consisting of ethylene, C₃-C₂₀α-olefins and a mixture of C₃-C₂₀ α-olefins; said monomers polymerizedin the presence of a late-transition-metal catalyst system in a reactionzone containing liquid phase, said process further comprising:

(A) feeding to said reaction zone a feedstream comprising said polarmonomer, either alone or in the presence of said olefinic monomer;

(B) when at least one α-olefin monomer is selected, continuouslyproviding said α-olefin as a dilute, liquefied α-olefin feed stream froma refinery or steam cracker, said feed stream containing diluent admixedtherewith wherein the amount of diluent in said feed stream is at least30 weight percent thereof;

(C) when ethylene is selected, continuously providing a feed streamcomprising ethylene in liquid, vapor, or liquid/vapor form;

(D) when a mixture of ethylene and an α-olefin is selected, admixing thefeed streams of steps (B) and (C) to provide a reactant feed streamhaving an α-olefin/ethylene weight ratio effective to yield a copolymercontaining an average ethylene sequence length, ESL, of from about 1.0to less than about 3.0;

(E) continuously introducing said feed streams derived in accordancewith steps (A), (B), (C) or (D) and late-transition-metal catalystsystem into the liquid phase of the reaction zone in a manner and underconditions sufficient to:

(i) polymerize the ethylene and/or α-olefin to copolymer product havinga number average molecular weight of not greater than 10,000;

(ii) obtain an α-olefin conversion, when an α-olefin is used as amonomer, of at least 30%;

(iii) obtain an ethylene conversion, where ethylene is used as amonomer, of at least 70%

(F) continuously withdrawing said copolymer from the reactor.

17. The process of aspect 16 wherein said olefinic monomer is selectedfrom olefin-containing refinery or steam cracker feedstreams.

18. The process of aspect 17 wherein said feedstream is selected fromthe group consisting of Raffinate-2, and C₃, C₄ or C₅ sources andmixtures thereof.

19. The process of aspect 16 wherein at least 50 weight % of theconstituents of said diluent possess a boiling point under reactionconditions within ±20° C. of the average boiling point of the α-olefinconstituents of the feed stream.

20. The process of aspect 16 or aspect 19 wherein the contents of thereaction zone are maintained at a temperature above the criticaltemperature of ethylene and below the critical temperature of aidα-olefin, as appropriate, when ethylene and/or at least one α-olefin ispresent.

21. The process of any of aspects 16 to 20 wherein said α-olefin monomercomprises at least one monomer selected from the group consisting ofbutene-1, propylene, and pentene-1 and said diluent comprisessubstantially nonpolymerizable C₃, C₄, C₅ hydrocarbons and mixturesthereof, other than said α-olefin monomer.

22. The process of any of aspects 16 to 21 wherein the polymerizationreaction temperature is controlled by evaporative cooling means.

23. The process of aspect 22 wherein in step (E) continuously the vaporabove the liquid phase is at least partially condensed and thecondensate is returned to said liquid phase.

24. The process of aspect 16 wherein said dilute liquefied α-olefin feedstream is derived from a refinery or steam cracker stream comprising atleast one α-olefin from which dienes, but not polar compounds, aresubstantially removed prior to introduction of said feed stream intosaid reactor.

25. A dispersant comprising a functionalized hydrocarbon copolymerderived from the copolymer of aspects 1 or 10 by reacting said copolymerwith a polyamine having one primary amino group and 1 to 10 secondary ortertiary amino groups.

26. The dispersant of aspect 25 wherein said copolymer from which it isderived initially contains an average of from about 1 to 6 polar groupsper copolymer chain.

27. The gel-free composition of aspect 25 wherein the reaction toproduce said derivatized copolymer is conducted in the presence of achain-stopping or end-capping co-reactant.

28. The composition of aspect 27 wherein said chain-stopping orend-capping co-reactant comprises C₁₂-C₄₀₀ hydrocarbyl substitutedsuccinic acid or anhydride; long chain monocarboxylic acid of formulaR_(a)COOH wherein R_(a) is C₁₂-C₄₀₀ hydrocarbyl; an amine containingonly a single reactive amino group per molecule; an alcohol having onlya single reactive hydroxy group per molecule; or mixtures thereof.

29. The composition of aspect 28 wherein said copolymer from which it isderived initially contains an average of from about 1 to about 2 polargroups per copolymer chain.

30. The reaction product of the copolymer of aspect 1 with an enophile.

31. The product of aspect 30 wherein said enophile is maleic anhydride.

32. The reaction product of aspect 31 further reacted with a memberselected from the group consisting of amines and alcohols.

33. The reaction product of aspect 30 wherein said reaction is initiatedusing one or more free radical generating compound and wherein saidreaction product contains an average of at least 2 of said copolymerchains linked to said enophile.

34. The reaction product of aspect 33 further reacted with polyamine andmonofunctional chain stopping agent.

35. The functionalized copolymer of aspect 1, wherein the copolymer isfurther functionalized with at least one member selected from the groupconsisting of C₃ to C₁₀ mono-unsaturated monocarboxylic acid producingmoieties and C₄ to C₁₀ mono-unsaturated dicarboxylic acid producingmoieties.

36. A functionalized copolymer comprising an oxidized copolymer, whereinsaid oxidized copolymer is the reaction product of the copolymer ofaspect 1 or aspect 6 and a gas selected from the group consisting of anoxygen-containing gas, an ozone-containing gas and mixtures thereof.

37. A derivatized copolymer useful as a lubricating oil dispersantadditive, which comprises the reaction product of the functionalizedcopolymer of any aspects 30 to 36 and a derivatizing compound.

38. The derivatized copolymer of aspect 37 in which the functionalizedcopolymer is reacted with at least one nucleophilic reagent selectedfrom amines, alcohols, metal reactants, and mixtures thereof.

39. The reaction product of aspect 30 in which the functionalizedcopolymer is further reacted with a heavy polyamine.

40. A derivatized copolymer comprising the reaction product of:

(a) at least one alkyl-substituted hydroxyaromatic compound formed bythe alkylation of at least one hydroxy aromatic compound with thecopolymer as in aspect 1;

(b) at least one aldehyde reactant; and

(c) at least one nucleophilic reactant.

41. The reaction product of the copolymer of aspect 1 further reactedwith a phenol in the presence of an acid catalyst.

42. The reaction produce of aspect 41 further reacted with a memberselected from the group consisting of aldehyde and polyamine.

43. The reaction product of aspect 42 in which said polyamine is a heavypolyamine.

44. A lubricating oil composition comprising a major amount of basestocklubricating oil of lubricating viscosity, and an effective amount of aviscosity modifier comprising hydrocarbon copolymer derived from atleast one polymerizable polar monomer and at least one polymerizableolefinic monomer, said copolymer suitable for use as a fuel or lubricantadditive, said copolymer having the following characteristics:

(a) an average ethylene sequence length, ESL, of from about 1.0 to lessthan about 3.0;

(b) an average of at least 5 branches per 100 carbon atoms of thecopolymer chains comprising said copolymer;

(c) at least about 50% of said branches being methyl and/or ethylbranches;

(d) substantially all of said incorporated polar monomer is present atthe terminal position of said branches;

(e) at least about 30% of said copolymer chains terminated with a vinylor vinylene group;

(f) a number average molecular weight, Mn, of from about 15,000 to about500,000; and

(g) substantial solubility in hydrocarbon and/or synthetic base oil.

45. A lubricating oil composition comprising a major amount of alubricating base oil, lubricating oil flow improver, and a minor amountof oil soluble copolymer as in aspect 44.

46. The lubricating oil composition of aspect 45, containing from 0.01to 5 weight percent of said lubricating oil flow improver and from 0.1to 20 weight percent of the said copolymer, based on the total weight ofthe composition.

47. An oil additive concentrate composition comprising hydrocarbonmineral oil diluent and about 2 to 50 wt. % based on the total amount ofhydrocarbon mineral oil diluent of hydrocarbon copolymer derived from atleast one polymerizable polar monomer and at least one polymerizableolefinic monomer, said copolymer suitable for use as a fuel or lubricantadditive, said copolymer having the following characteristics:

(a) an average ethylene sequence length, ESL, of from about 1.0 to lessthan about 3.0;

(b) an average of at least 5 branches per 100 carbon atoms of thecopolymer chains comprising said copolymer;

(c) at least about 50% of said branches being methyl and/or ethylbranches;

(d) substantially all of said incorporated polar monomer is present atthe terminal position of said branches;

(e) at least about 30% of said copolymer chains terminated with a vinylor vinylene group;

(f) substantial solubility in hydrocarbon and/or synthetic base oil.

48. The oil additive concentrate according to aspect 47, wherein saidcopolymer has a number average molecular weight, Mn, of from about 300to about 10,000.

49. The oil additive concentrate according to aspect 47, wherein saidcopolymer has a number average molecular weight of from about 11,000 toabout 500,000.

50. An oil additive concentrate composition comprising hydrocarbonmineral oil diluent and about 2 to 50 wt. % based on the total amount ofhydrocarbon mineral oil diluent of a derivatized copolymer useful as alubricating oil dispersant additive, which derivatized copolymercomprises the reaction product of the functionalized copolymer of any ofaspects 30 to 36.

51. A lubricating oil composition base oil and, as a dispersantadditive, a functionalized or derivatized copolymer as in any of aspects30 to 40, in the form of either:

(a) a concentrate containing from 11 to 80 weight percent of saiddispersant additive; or

(b) a composition containing from 0.1 to 10 weight percent of saiddispersant additive.

52. A fuel oil composition comprising base oil and, as a dispersantadditive, a functionalized or derivatized copolymer as in any of aspects30 to 40, in the form of either:

(a) a concentrate containing from 11 to 80 weight percent of saiddispersant additive; or

(b) a composition containing from 0.001 to 0.1 weight percent of saiddispersant additive.

53. A process for continuously producing hydrocarbon copolymer suitablefor use as a fuel or lubricant additive, said copolymer derived from atleast one polymerizable polar monomer selected from α, β unsaturatedcarbonyl compounds represented by the formula:

wherein X is hydrogen (H), NH₂, R_(y) or OR_(y); R_(x) is H or a C₁-C₅straight or branched alkyl group and R_(y) is H or a C₁ to C₂₀ straightor branched alkyl group; for short chain unsaturated ester monomers,R_(y) is preferably a C₁-C₅ alkyl group an for long chain monomers,preferably a C₁₀ to C₁₈ alkyl group; and at least one polymerizableolefinic monomer selected from the group consisting of ethylene, C₃-C₂₀α-olefins and a mixture of C₃-C₂₀ α-olefins and polymerized in thepresence of a late-transition-metal catalyst system in a reaction zonecontaining liquid phase, said process further comprising:

(A) when at least one α-olefin monomer is selected, continuouslyproviding said α-olefin as a dilute, liquefied α-olefin feed stream froma refinery or steam cracker, said feed stream comprising diluent admixedtherewith wherein the amount of diluent in said feed stream is at least30 weight percent thereof;

(B) when ethylene is selected, continuously providing a feed streamcomprising ethylene in liquid, vapor, or liquid/vapor form;

(C) when a mixture of ethylene and an α-olefin is selected, admixing thefeed streams of steps (A) and (B) to provide a reactant feed streamhaving an α-olefin/ethylene weight ratio effective to yield a copolymercontaining an average ethylene sequence length, ESL, of from about 1.0to less than about 3.0;

(D) continuously introducing said feed stream or said reactant feedstream derived in accordance with steps (A), (B) or (C) as well as afeed stream of said polar monomer, and a late-transition-metal catalystsystem into the liquid phase of the reaction zone in a manner and underconditions sufficient to:

(i) polymerize the ethylene and/or α-olefin to copolymer product havinga number average molecular weight suitable for use as a fuel orlubricant additive;

(ii) obtain an α-olefin conversion, when an α-olefin is used as amonomer, of at least 30%;

(iii) obtain an ethylene conversion, where ethylene is used as amonomer, of at least 70%

(E) continuously withdrawing said copolymer from the reactor.

We claim:
 1. Hydrocarbon copolymer derived from at least onepolymerizable polar monomer and at least one polymerizable olefinicmonomer, said polar monomer selected from α, β unsaturated carbonylcompounds represented by the formula:

wherein X is hydrogen (H), NH₂, R_(y) or OR_(y); R_(x) is H or a C₁-C₅straight or branched alkyl group and R_(y), is H or a C₁ to C₂₀ straightor branched alkyl group; said copolymer suitable for use as a fuel orlubricant additive, said copolymer having the following characteristics:(a) an average ethylene sequence length, ESL, of from about 1.0 to lessthan about 3.0; (b) an average of at least 5 branches per 100 carbonatoms of the copolymer chains comprising said copolymer; (c) at leastabout 50% of said branches being methyl and/or ethyl branches; (d)substantially all of said incorporated polar monomer is present at theterminal position of said branches; (e) at least about 30% of saidcopolymer chains terminated with a vinyl or vinylene group; (f) a numberaverage molecular weight, Mn, of from about 15,000 to about 500,000; and(g) substantial solubility in hydrocarbon and/or synthetic base oil. 2.The copolymer of claim 1 wherein the incorporated polar moiety derivedfrom said polymerizable polar monomer which is incorporated in saidcopolymer is present at an average concentration of from about one polarmoiety for each 5,000 Mn segment of polymer backbone, includingbranches, to about one polar moiety for each 1,000 Mn segment.
 3. Thecopolymer of claim 2 wherein said polar monomer is selected from thegroup consisting of methyl acrylate, ethyl acrylate, tert-butylacrylate, methyl methacrylate, methyl ethylacrylate, ethyl methacrylate,ethyl ethylacrylate, methyl vinyl ketone and acrylamide.
 4. Thecopolymer of claim 3 wherein said olefinic monomer is selected from thegroup consisting of ethylene, propylene and butene-1.
 5. A lubricatingoil composition comprising a major amount of basestock lubricating oilof lubricating viscosity, and an effective amount of a viscositymodifier comprising the hydrocarbon copolymer of claim
 1. 6. Alubricating oil composition comprising a major amount of a lubricatingbase oil, lubricating oil flow improver, and a minor amount of thehydrocarbon copolymer of claim
 1. 7. An oil additive concentratecomposition comprising hydrocarbon mineral oil diluent and about 2 to 50wt. % based on the total amount of hydrocarbon mineral oil diluent ofthe hydrocarbon copolymer of claim
 1. 8. The copolymer of claim 1wherein R_(y) is selected from the group consisting of C₁-C₅ alkyl forshort chain unsaturated ester monomers and a C₁₀ to C₁₈ alkyl for longchain monomers.
 9. A composition of matter suitable for use as a fuel orlubricant additive consisting essentially of hydrocarbon copolymerderived from at least one polymerizable polar monomer and at least onepolymerizable olefinic monomer; said copolymer having at least twonitrogen atoms incorporated therein; said polar monomer selected from α,β unsaturated carbonyl compounds represented by the formula:

wherein X is hydrogen (H), NH₂, R_(y) or OR_(y); R_(x) is H or a C₁-C₅straight or branched alkyl group; said olefinic monomer group and R_(y)is H or a C₁ to C₂₀ straight or branched alkyl group; said olefinicmonomer selected from the group consisting of ethylene, C₃-C₂₀ α-olefinsand a mixture of C₃-C₂₀ α-olefins; said copolymer having the followingcharacteristics: (a) an average ethylene sequence length, ESL, of fromabout 1.0 to less than about 3.0; (b) an average of at least 5 branchesper 100 carbon atoms of the copolymer chains comprising said copolymer;(c) at least about 50% of said branches being methyl and/or ethylbranches; (d) substantially all of said incorporated polar monomer ispresent at the terminal position of said branches; (e) at least about30% of said copolymer chains terminated with a vinyl or vinylene group;(f) a number average molecular weight, Mn, of from about 15,000 to about500,000; and (g) substantial solubility in hydrocarbon and/or syntheticbase oil.
 10. The composition of matter of claim 9 wherein theincorporated polar moiety derived from said polymerizable polar monomerwhich is incorporated in said copolymer is present at an averageconcentration of from about one polar moiety for each 5,000 Mn segmentof polymer backbone, including branches, to about one polar moiety foreach 1,000 Mn segment.
 11. The composition of matter of claim 10 whereinsaid polar monomer is selected from the group consisting of methylacrylate, ethyl acrylate, tert-butyl acrylate, methyl methacrylate,methyl ethylacrylate, ethyl methacrylate, ethyl ethylacrylate, methylvinyl ketone, and acrylamide.
 12. The composition of matter of claim 11wherein said olefinic monomer is selected from the group consisting ofethylene, propylene and butene-1.
 13. A viscosity index improvercomprising a functionalized hydrocarbon copolymer derived from thecopolymer of claims 1 or 9 by reacting said copolymer with a polyaminehaving one primary amino group and 1 to 10 secondary or tertiary aminogroups.
 14. The viscosity index improver of claim 13 wherein saidcopolymer from which it is derived initially contains an average of fromabout 1 to about 6 polar groups per copolymer chain.
 15. The gel-freecomposition of claim 13 wherein the reaction to produce said derivatizedcopolymer is conducted in the presence of a chain-stopping orend-capping co-reactant.
 16. The composition of claim 15 wherein saidchain-stopping or end-capping co-reactant comprises C₁₂-C₄₀₀ hydrocarbylsubstituted succinic acid or anhydride; long chain monocarboxylic acidof the formula R_(a)COOH wherein R_(a) is C₁₂-C₄₀₀ hydrocarbyl; an aminecontaining only a single reactive amino group per molecule; an alcoholhaving only a single reactive hydroxy group per molecule; or mixturesthereof.
 17. The composition of claim 16 wherein said copolymer fromwhich it is derived initially contains an average of from about 1 toabout 2 polar groups per copolymer chain.
 18. A derivatized copolymeruseful as a lubricating oil viscosity index improver additive, whichcomprises the reaction product of the functionalized copolymer of claim13 and a derivatizing compound.
 19. An oil additive concentratecomposition comprising hydrocarbon mineral oil diluent and about 2 to 50wt. % based on the total amount of hydrocarbon mineral oil diluent ofthe derivatized copolymer of claim
 18. 20. A lubricating oil or fuelcomposition comprising base oil and, as a viscosity index improveradditive, a functionalized or derivatized copolymer as claimed in claim13, in the form of either: (a) a lubricating oil concentrate containingfrom 11 to 80 weight percent of said additive; or (b) a lubricating oilcomposition containing from 0.1 to 10 weight percent of said additive;or (c) a fuel oil concentrate containing from 11 to 80 weight percent ofsaid additive; or (d) a fuel oil composition containing from 0.001 to0.1 weight percent of said additive.
 21. The composition of claim 20wherein said copolymer has a number average molecular weight, Mn, offrom about 15,000 to about 500,000.
 22. The composition of matter ofclaim 9 wherein R_(y) is selected from the group consisting of a C₁-C₅alkyl for short chain unsaturated ester monomers and a C₁₀ to C₁₈ alkylfor long chain monomers.
 23. A lubricating oil or fuel compositioncomprising base oil and, as a viscosity index improver additive, afunctionalized or derivatized copolymer as claimed in claim 18, in theform of either: (a) a lubricating oil concentrate containing from 11 to80 weight percent of said additive; or (b) a lubricating oil compositioncontaining from 0.1 to 10 weight percent of said additive; or (c) a fueloil concentrate containing from 11 to 80 weight percent of saidadditive; or (d) a fuel oil composition containing from 0.001 to 0.1weight percent of said additive.